Science.gov

Sample records for modulator cdb4124 inhibits

  1. Endometrial changes from short-term therapy with CDB-4124, a selective progesterone receptor modulator.

    PubMed

    Ioffe, Olga B; Zaino, Richard J; Mutter, George L

    2009-03-01

    Selective progesterone receptor modulators are a class of drugs with progesterone antagonist activity that may confer therapeutic benefit for reproductive disorders in premenopausal women. Endometrial structure, which is dynamically controlled by circulating sex hormones, is likely to be perturbed by progesterone receptor modulators through their progesterone antagonist properties. We examined endometrial histology in 58 premenopausal women treated with the progesterone receptor modulator CDB-4124 (also known as Proellex) for endometriosis or uterine leiomyomata in two clinical trials. Endometrial biopsies obtained after 3 or 6 months with doses of 12.5, 25, or 50 mg daily oral CDB-4124 were reviewed independently by three pathologists. Consensus diagnoses using the World Health Organization hyperplasia scoring system, comments on specific histologic features, and clinical annotation were collected and analyzed. The majority of the endometrial biopsies (103 of 174 biopsies) contained histologic changes that are not seen during normal menstrual cycles. The histology of CDB-4124-treated patients was generally inactive or atrophic, and less frequently, proliferative or secretory, superimposed upon which were novel changes including formation of cystically dilated glands, and secretory changes coexisting with mitoses and apoptotic bodies. With increasing treatment dose and duration, the cysts became predominant and their lining inactive or atrophic. Cystic glands in the CDB-4124-treated subjects correlated with increased endometrial thickness by ultrasound. None of the CDB-4124-treated patients developed endometrial carcinoma or hyperplasia while on therapy. CDB-4124 therapy for 3-6 months produces histologic changes that are sufficiently novel that they might easily be misinterpreted by pathologists, particularly as disordered proliferative or hyperplastic endometrium. Knowledge of the constellation of endometrial changes associated with this agent and other

  2. Can Arousal Modulate Response Inhibition?

    ERIC Educational Resources Information Center

    Weinbach, Noam; Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai

    2015-01-01

    The goal of the present study was to examine if and how arousal can modulate response inhibition. Two competing hypotheses can be drawn from previous literature. One holds that alerting cues that elevate arousal should result in an impulsive response and therefore impair response inhibition. The other suggests that alerting enhances processing of…

  3. Speech-induced modulation of interhemispheric inhibition.

    PubMed

    Kano, Tadashige; Kobayashi, Masahito; Ohira, Takayuki; Yoshida, Kazunari

    2012-12-01

    This study aimed to determine the effects of speech and mastication on interhemispheric inhibition between the right and left primary motor areas (M1s) by using transcranial magnetic stimulation (TMS). Motor-evoked potentials (MEPs) were recorded from the first dorsal interossei (FDIs) of each hand of 10 healthy right-handed subjects under 3 conditions: at rest (control), during mastication (non-verbal oral movement), and during speech (reading aloud). Test TMS was delivered following conditioning TMS of the contralateral M1 at various interstimulus intervals. Under all conditions, the MEPs in the left FDIs were significantly inhibited after conditioning of the left M1 (i.e. inhibition of the right M1 by TMS of the left hemisphere). In contrast, the left M1 was significantly inhibited by the right hemisphere only during the control and mastication tasks, but not speech task. These results suggest that speech may facilitate the activity of the dominant M1 via functional connectivity between the speech area and the left M1, or may modify the balance of interhemispheric interactions, by suppressing inhibition of the dominant hemisphere by the non-dominant hemisphere. Our findings show a novel aspect of interhemispheric dominance and may improve therapeutic strategies for recovery from stroke. PMID:23123786

  4. Modulation of Potassium Channels Inhibits Bunyavirus Infection*

    PubMed Central

    Hover, Samantha; King, Barnabas; Hall, Bradley; Loundras, Eleni-Anna; Taqi, Hussah; Daly, Janet; Dallas, Mark; Peers, Chris; Schnettler, Esther; McKimmie, Clive; Kohl, Alain; Barr, John N.; Mankouri, Jamel

    2016-01-01

    Bunyaviruses are considered to be emerging pathogens facilitated by the segmented nature of their genome that allows reassortment between different species to generate novel viruses with altered pathogenicity. Bunyaviruses are transmitted via a diverse range of arthropod vectors, as well as rodents, and have established a global disease range with massive importance in healthcare, animal welfare, and economics. There are no vaccines or anti-viral therapies available to treat human bunyavirus infections and so development of new anti-viral strategies is urgently required. Bunyamwera virus (BUNV; genus Orthobunyavirus) is the model bunyavirus, sharing aspects of its molecular and cellular biology with all Bunyaviridae family members. Here, we show for the first time that BUNV activates and requires cellular potassium (K+) channels to infect cells. Time of addition assays using K+ channel modulating agents demonstrated that K+ channel function is critical to events shortly after virus entry but prior to viral RNA synthesis/replication. A similar K+ channel dependence was identified for other bunyaviruses namely Schmallenberg virus (Orthobunyavirus) as well as the more distantly related Hazara virus (Nairovirus). Using a rational pharmacological screening regimen, two-pore domain K+ channels (K2P) were identified as the K+ channel family mediating BUNV K+ channel dependence. As several K2P channel modulators are currently in clinical use, our work suggests they may represent a new and safe drug class for the treatment of potentially lethal bunyavirus disease. PMID:26677217

  5. Modulation of Potassium Channels Inhibits Bunyavirus Infection.

    PubMed

    Hover, Samantha; King, Barnabas; Hall, Bradley; Loundras, Eleni-Anna; Taqi, Hussah; Daly, Janet; Dallas, Mark; Peers, Chris; Schnettler, Esther; McKimmie, Clive; Kohl, Alain; Barr, John N; Mankouri, Jamel

    2016-02-12

    Bunyaviruses are considered to be emerging pathogens facilitated by the segmented nature of their genome that allows reassortment between different species to generate novel viruses with altered pathogenicity. Bunyaviruses are transmitted via a diverse range of arthropod vectors, as well as rodents, and have established a global disease range with massive importance in healthcare, animal welfare, and economics. There are no vaccines or anti-viral therapies available to treat human bunyavirus infections and so development of new anti-viral strategies is urgently required. Bunyamwera virus (BUNV; genus Orthobunyavirus) is the model bunyavirus, sharing aspects of its molecular and cellular biology with all Bunyaviridae family members. Here, we show for the first time that BUNV activates and requires cellular potassium (K(+)) channels to infect cells. Time of addition assays using K(+) channel modulating agents demonstrated that K(+) channel function is critical to events shortly after virus entry but prior to viral RNA synthesis/replication. A similar K(+) channel dependence was identified for other bunyaviruses namely Schmallenberg virus (Orthobunyavirus) as well as the more distantly related Hazara virus (Nairovirus). Using a rational pharmacological screening regimen, two-pore domain K(+) channels (K2P) were identified as the K(+) channel family mediating BUNV K(+) channel dependence. As several K2P channel modulators are currently in clinical use, our work suggests they may represent a new and safe drug class for the treatment of potentially lethal bunyavirus disease.

  6. Divisive gain modulation of motoneurons by inhibition optimizes muscular control.

    PubMed

    Vestergaard, Mikkel; Berg, Rune W

    2015-02-25

    When using muscles, the precision with which force is delivered is as important as the delivery of force itself. Force is regulated by both the number of recruited motoneurons and their spike frequency. While it is known that the recruitment is ordered to reduce variability in force, it remains unclear whether the motoneuron gain, i.e., the slope of the transformation between synaptic input and spiking output, is also modulated to reduce variability in force. To address this issue, we use turtle hindlimb scratching as a model for fine motor control, since this behavior involves precise limb movement to rub the location of somatic nuisance touch. We recorded intracellularly from motoneurons in a reduced preparation where the limbs were removed to increase mechanical stability and the motor nerve activity served as a surrogate for muscle force. We found that not only is the gain of motoneurons regulated on a subsecond timescale, it is also adjusted to minimize variability. The modulation is likely achieved via an expansive nonlinearity between spike rate and membrane potential with inhibition having a divisive influence. These findings reveal a versatile mechanism of modulating neuronal sensitivity and suggest that such modulation is fundamentally linked to optimization.

  7. Temporal expectancy modulates inhibition of return in a discrimination task.

    PubMed

    Gabay, Shai; Henik, Avishai

    2010-02-01

    This research examined the influence of cue temporal predictability on inhibition of return (IOR) in a discrimination task. In exogenous attention experiments, the cue that summons attention is noninformative as to where the target will appear. However, it is predictive as to when it will appear. In previous work, it was demonstrated that temporal predictability does not influence IOR in detection tasks. In this work, it is shown that IOR is influenced by temporal predictability in discrimination tasks. Predictability was manipulated by using three stimulus onset asynchrony distributions: nonaging, aging, and accelerated aging. IOR was found when the cue predicted target appearance and was modulated by temporal information. In the nonaging distribution (in which the cue did not predict target appearance), there was no IOR.

  8. Prepulse inhibition modulation by contextual conditioning of dopaminergic activity.

    PubMed

    Mena, Auxiliadora; De la Casa, Luis G

    2013-09-01

    When a neutral stimulus is repeatedly paired with a drug, an association is established between them that can induce two different responses: either an opponent response that counteracts the effect of the drug, or a response that is similar to that induced by the drug. In this paper, we focus on the analysis of the associations that can be established between the contextual cues and the administration of dopamine agonists or antagonists. Our hypothesis suggests that repeated administration of drugs that modulate dopaminergic activity in the presence of a specific context leads to the establishment of an association that subsequently results in a conditioned response to the context that is similar to that induced by the drug. To test this hypothesis, we conducted two experiments that revealed that contextual cues acquired the property to modulate pre-pulse inhibition by prior pairings of such context with the dopamine antagonist haloperidol (Experiment 1), and with the dopamine agonist d-amphetamine (Experiment 2). The implications of these results are discussed both at a theoretical level, and attending to the possibilities that could involve the use of context cues for the therapeutic administration of dopaminergic drugs.

  9. Lithium chloride modulates chondrocyte primary cilia and inhibits Hedgehog signaling.

    PubMed

    Thompson, Clare L; Wiles, Anna; Poole, C Anthony; Knight, Martin M

    2016-02-01

    Lithium chloride (LiCl) exhibits significant therapeutic potential as a treatment for osteoarthritis. Hedgehog signaling is activated in osteoarthritis, where it promotes chondrocyte hypertrophy and cartilage matrix catabolism. Hedgehog signaling requires the primary cilium such that maintenance of this compartment is essential for pathway activity. Here we report that LiCl (50 mM) inhibits Hedgehog signaling in bovine articular chondrocytes such that the induction of GLI1 and PTCH1 expression is reduced ​ by 71 and 55%, respectively. Pathway inhibition is associated with a 97% increase in primary cilia length from 2.09 ± 0.7 μm in untreated cells to 4.06 ± 0.9 μm in LiCl-treated cells. We show that cilia elongation disrupts trafficking within the axoneme with a 38% reduction in Arl13b ciliary localization at the distal region of the cilium, consistent with the role of Arl13b in modulating Hedgehog signaling. In addition, we demonstrate similar increases in cilia length in human chondrocytes in vitro and after administration of dietary lithium to Wistar rats in vivo. Our data provide new insights into the effects of LiCl on chondrocyte primary cilia and Hedgehog signaling and shows for the first time that pharmaceutical targeting of the primary cilium may have therapeutic benefits in the treatment of osteoarthritis. PMID:26499268

  10. Polyamine depletion inhibits the autophagic response modulating Trypanosoma cruzi infectivity

    PubMed Central

    Vanrell, María C.; Cueto, Juan A.; Barclay, Jeremías J.; Carrillo, Carolina; Colombo, María I.; Gottlieb, Roberta A.; Romano, Patricia S.

    2013-01-01

    Autophagy is a cell process that in normal conditions serves to recycle cytoplasmic components and aged or damaged organelles. The autophagic pathway has been implicated in many physiological and pathological situations, even during the course of infection by intracellular pathogens. Many compounds are currently used to positively or negatively modulate the autophagic response. Recently it was demonstrated that the polyamine spermidine is a physiological inducer of autophagy in eukaryotic cells. We have previously shown that the etiological agent of Chagas disease, the protozoan parasite Trypanosoma cruzi, interacts with autophagic compartments during host cell invasion and that preactivation of autophagy significantly increases host cell colonization by this parasite. In the present report we have analyzed the effect of polyamine depletion on the autophagic response of the host cell and on T. cruzi infectivity. Our data showed that depleting intracellular polyamines by inhibiting the biosynthetic enzyme ornithine decarboxylase with difluoromethylornithine (DFMO) suppressed the induction of autophagy in response to starvation or rapamycin treatment in two cell lines. This effect was associated with a decrease in the levels of LC3 and ATG5, two proteins required for autophagosome formation. As a consequence of inhibiting host cell autophagy, DFMO impaired T. cruzi colonization, indicating that polyamines and autophagy facilitate parasite infection. Thus, our results point to DFMO as a novel autophagy inhibitor. While other autophagy inhibitors such as wortmannin and 3-methyladenine are nonspecific and potentially toxic, DFMO is an FDA-approved drug that may have value in limiting autophagy and the spread of the infection in Chagas disease and possibly other pathological settings. PMID:23697944

  11. Learning to integrate versus inhibiting information is modulated by age.

    PubMed

    Cappelletti, Marinella; Pikkat, Helen; Upstill, Emily; Speekenbrink, Maarten; Walsh, Vincent

    2015-02-01

    Cognitive training aiming at improving learning is often successful, but what exactly underlies the observed improvements and how these differ across the age spectrum are currently unknown. Here we asked whether learning in young and older people may reflect enhanced ability to integrate information required to perform a cognitive task or whether it may instead reflect the ability to inhibit task-irrelevant information for successful task performance. We trained 30 young and 30 aging human participants on a numerosity discrimination task known to engage the parietal cortex and in which cue-integration and inhibitory abilities can be distinguished. We coupled training with parietal, motor, or sham transcranial random noise stimulation, known for modulating neural activity. Numerosity discrimination improved after training and was maintained long term, especially in the training + parietal stimulation group, regardless of age. Despite the quantitatively similar improvement in the two age groups, the content of learning differed remarkably: aging participants improved more in inhibitory abilities, whereas younger subjects improved in cue-integration abilities. Moreover, differences in the content of learning were reflected in different transfer effects to untrained but related abilities: in the younger group, improvements in cue integration paralleled improvements in continuous quantity (time and space), whereas in the elderly group, improvements in numerosity-based inhibitory abilities generalized to other measures of inhibition and corresponded to a decline in space discrimination, possibly because conflicting learning resources are used in numerosity and continuous quantity processing. These results indicate that training can enhance different, age-dependent cognitive processes and highlight the importance of identifying the exact processes underlying learning for effective training programs.

  12. Effect of structural modulation of polyphenolic compounds on the inhibition of Escherichia coli ATP synthase

    PubMed Central

    Ahmad, Zulfiqar; Ahmad, Mubeen; Okafor, Florence; Jones, Jeanette; Abunameh, Abdel M; Cheniya, Rakesh K; Kady, Ismail O

    2012-01-01

    In this paper we present the inhibitory effect of a variety of structurally modulated/modified polyphenolic compounds on purified F1 or membrane bound F1Fo E. coli ATP synthase. Structural modulation of polyphenols with two phenolic rings inhibited ATP synthase essentially completely; one or three ringed polyphenols individually or fused together inhibited partially. We found that the position of hydroxyl and nitro groups play critical role in the degree of binding and inhibition of ATPase activity. The extended positioning of hydroxyl groups on imino diphenolic compounds diminished the inhibition and abridged position enhanced the inhibition potency. This was contrary to the effect by simple single ringed phenolic compounds where extended positioning of hydroxyl group was found to be effective for inhibition. Also, introduction of nitro group augmented the inhibition on molar scale in comparison to the inhibition by resveratrol but addition of phosphate group did not. Similarly, aromatic diol or triol with rigid or planar ring structure and no free rotation poorly inhibited the ATPase activity. The inhibition was identical in both F1Fo membrane preparations as well as in isolated purified F1 and was reversible in all cases. Growth assays suggested that modulated compounds used in this study inhibited F1-ATPase as well as ATP synthesis nearly equally. PMID:22285988

  13. Simulating Cortical Feedback Modulation as Changes in Excitation and Inhibition in a Cortical Circuit Model.

    PubMed

    Zagha, Edward; Murray, John D; McCormick, David A

    2016-01-01

    Cortical feedback pathways are hypothesized to distribute context-dependent signals during flexible behavior. Recent experimental work has attempted to understand the mechanisms by which cortical feedback inputs modulate their target regions. Within the mouse whisker sensorimotor system, cortical feedback stimulation modulates spontaneous activity and sensory responsiveness, leading to enhanced sensory representations. However, the cellular mechanisms underlying these effects are currently unknown. In this study we use a simplified neural circuit model, which includes two recurrent excitatory populations and global inhibition, to simulate cortical modulation. First, we demonstrate how changes in the strengths of excitation and inhibition alter the input-output processing responses of our model. Second, we compare these responses with experimental findings from cortical feedback stimulation. Our analyses predict that enhanced inhibition underlies the changes in spontaneous and sensory evoked activity observed experimentally. More generally, these analyses provide a framework for relating cellular and synaptic properties to emergent circuit function and dynamic modulation. PMID:27595137

  14. Simulating Cortical Feedback Modulation as Changes in Excitation and Inhibition in a Cortical Circuit Model

    PubMed Central

    Murray, John D.; McCormick, David A.

    2016-01-01

    Abstract Cortical feedback pathways are hypothesized to distribute context-dependent signals during flexible behavior. Recent experimental work has attempted to understand the mechanisms by which cortical feedback inputs modulate their target regions. Within the mouse whisker sensorimotor system, cortical feedback stimulation modulates spontaneous activity and sensory responsiveness, leading to enhanced sensory representations. However, the cellular mechanisms underlying these effects are currently unknown. In this study we use a simplified neural circuit model, which includes two recurrent excitatory populations and global inhibition, to simulate cortical modulation. First, we demonstrate how changes in the strengths of excitation and inhibition alter the input–output processing responses of our model. Second, we compare these responses with experimental findings from cortical feedback stimulation. Our analyses predict that enhanced inhibition underlies the changes in spontaneous and sensory evoked activity observed experimentally. More generally, these analyses provide a framework for relating cellular and synaptic properties to emergent circuit function and dynamic modulation.

  15. Simulating Cortical Feedback Modulation as Changes in Excitation and Inhibition in a Cortical Circuit Model.

    PubMed

    Zagha, Edward; Murray, John D; McCormick, David A

    2016-01-01

    Cortical feedback pathways are hypothesized to distribute context-dependent signals during flexible behavior. Recent experimental work has attempted to understand the mechanisms by which cortical feedback inputs modulate their target regions. Within the mouse whisker sensorimotor system, cortical feedback stimulation modulates spontaneous activity and sensory responsiveness, leading to enhanced sensory representations. However, the cellular mechanisms underlying these effects are currently unknown. In this study we use a simplified neural circuit model, which includes two recurrent excitatory populations and global inhibition, to simulate cortical modulation. First, we demonstrate how changes in the strengths of excitation and inhibition alter the input-output processing responses of our model. Second, we compare these responses with experimental findings from cortical feedback stimulation. Our analyses predict that enhanced inhibition underlies the changes in spontaneous and sensory evoked activity observed experimentally. More generally, these analyses provide a framework for relating cellular and synaptic properties to emergent circuit function and dynamic modulation.

  16. Simulating Cortical Feedback Modulation as Changes in Excitation and Inhibition in a Cortical Circuit Model

    PubMed Central

    Murray, John D.; McCormick, David A.

    2016-01-01

    Abstract Cortical feedback pathways are hypothesized to distribute context-dependent signals during flexible behavior. Recent experimental work has attempted to understand the mechanisms by which cortical feedback inputs modulate their target regions. Within the mouse whisker sensorimotor system, cortical feedback stimulation modulates spontaneous activity and sensory responsiveness, leading to enhanced sensory representations. However, the cellular mechanisms underlying these effects are currently unknown. In this study we use a simplified neural circuit model, which includes two recurrent excitatory populations and global inhibition, to simulate cortical modulation. First, we demonstrate how changes in the strengths of excitation and inhibition alter the input–output processing responses of our model. Second, we compare these responses with experimental findings from cortical feedback stimulation. Our analyses predict that enhanced inhibition underlies the changes in spontaneous and sensory evoked activity observed experimentally. More generally, these analyses provide a framework for relating cellular and synaptic properties to emergent circuit function and dynamic modulation. PMID:27595137

  17. Central Inhibition Ability Modulates Attention-Induced Motion Blindness

    ERIC Educational Resources Information Center

    Milders, Maarten; Hay, Julia; Sahraie, Arash; Niedeggen, Michael

    2004-01-01

    Impaired motion perception can be induced in normal observers in a rapid serial visual presentation task. Essential for this effect is the presence of motion distractors prior to the motion target, and we proposed that this attention-induced motion blindness results from high-level inhibition produced by the distractors. To investigate this, we…

  18. Strategic modulation of response inhibition in task-switching

    PubMed Central

    Grzyb, Kai Robin; Hübner, Ronald

    2013-01-01

    Residual activations from previous task performance usually prime the system toward response repetition. However, when the task switches, the repetition of a response (RR) produces longer reaction times and higher error rates. Some researchers assumed that these RR costs reflect strategic inhibition of just executed responses and that this serves for preventing perseveration errors. We investigated whether the basic level of response inhibition is adapted to the overall risk of response perseveration. In a series of 3 experiments, we presented different proportions of stimuli that carry either a high or a low risk of perseveration. Additionally, the discriminability of high- and low-risk stimuli was varied. The results indicate that individuals apply several processing and control strategies, depending on the mixture of stimulus types. When discriminability was high, control was adapted on a trial-by trial basis, which presumably reduces mental effort (Experiment 1). When trial-based strategies were prevented, RR costs for low-risk stimuli varied with the overall proportion of high-risk stimuli (Experiments 2 and 3), indicating an adaptation of the basic level of response inhibition. PMID:23986730

  19. Synthesis and SAR study of modulators inhibiting tRXRα-dependent AKT activation

    PubMed Central

    Wang, Zhi-Gang; Chen, Liqun; Chen, Jiebo; Zheng, Jian-Feng; Gao, Weiwei; Zeng, Zhiping; Zhou, Hu; Zhang, Xiao-kun; Huang, Pei-Qiang; Su, Ying

    2013-01-01

    RXRα represents an intriguing and unique target for pharmacologic interventions. We recently showed that Sulindac and a designed analog could bind to RXRα and modulate its biological activity, including inhibition of the interaction of an N-terminally truncated RXRα (tRXRα) with the p85α regulatory subunit of phosphatidylinositol-3-OH kinase (PI3K). Here we report the synthesis, testing and SAR of a series of novel analogs of Sulindac as potential modulators for inhibiting tRXRα-dependent AKT activation. A new compound 30 was identified to have improved biological activity. PMID:23434637

  20. Inhibition of chaotic escape from a potential well using small parametric modulations

    SciTech Connect

    Chacon, R.; Balibrea, F.; Lopez, M.A.

    1996-11-01

    It is shown theoretically for the first time that, depending on its period, amplitude, and initial phase, a periodic parametric modulation can suppress a chaotic escape from a potential well. The instance of the Helmholtz oscillator is used to demonstrate, by means of Melnikov{close_quote}s method, that parametric modulations of the linear or quadratic potential terms inhibit chaotic escape when certain resonance conditions are met. {copyright} {ital 1996 American Institute of Physics.}

  1. Foxp3+ T cells inhibit antitumor immune memory modulated by mTOR inhibition.

    PubMed

    Wang, Yanping; Sparwasser, Tim; Figlin, Robert; Kim, Hyung L

    2014-04-15

    Inhibition of mTOR signaling enhances antitumor memory lymphocytes. However, pharmacologic mTOR inhibition also enhances regulatory T-cell (Treg) activity. To counter this effect, Treg control was added to mTOR inhibition in preclinical models. Tregs were controlled with CD4-depleting antibodies because CD4 depletion has high translational potential and already has a well-established safety profile in patients. The antitumor activity of the combination therapy was CD8 dependent and controlled growth of syngeneic tumors even when an adoptive immunotherapy was not used. Lymphocytes resulting from the combination therapy could be transferred into naïve mice to inhibit aggressive growth of lung metastases. The combination therapy enhanced CD8 memory formation as determined by memory markers and functional studies of immune recall. Removal of FoxP3-expressing T lymphocytes was the mechanism underlying immunologic memory formation following CD4 depletion. This was confirmed using transgenic DEREG (depletion of regulatory T cells) mice to specifically remove Foxp3(+) T cells. It was further confirmed with reciprocal studies where stimulation of immunologic memory because of CD4 depletion was completely neutralized by adoptively transferring tumor-specific Foxp3(+) T cells. Also contributing to tumor control, Tregs that eventually recovered following CD4 depletion were less immunosuppressive. These results provide a rationale for further study of mTOR inhibition and CD4 depletion in patients.

  2. Diminished appetitive startle modulation following targeted inhibition of prefrontal cortex.

    PubMed

    Hurlemann, René; Arndt, Stephan; Schlaepfer, Thomas E; Reul, Juergen; Maier, Wolfgang; Scheele, Dirk

    2015-01-01

    From an evolutionary perspective the startle eye-blink response forms an integral part of the human avoidance behavioral repertoire and is typically diminished by pleasant emotional states. In major depressive disorder (MDD) appetitive motivation is impaired, evident in a reduced interference of positive emotion with the startle response. Given the pivotal role of frontostriatal neurocircuitry in orchestrating appetitive motivation, we hypothesized that inhibitory transcranial magnetic stimulation (TMS) would reduce appetitive neuromodulation in a manner similar to MDD. Based on a pre-TMS functional MRI (fMRI) experiment we selected the left dorsolateral and dorsomedial prefrontal cortices as target regions for subsequent sham-controlled inhibitory theta-burst TMS (TBS) in 40 healthy male volunteers. Consistent with our hypothesis, between-group comparisons revealed a TBS-induced inhibition of appetitive neuromodulation, manifest in a diminished startle response suppression by hedonic stimuli. Collectively, our results suggest that functional integrity of left dorsolateral and dorsomedial prefrontal cortex is critical for mediating a pleasure-induced down-regulation of avoidance responses which may protect the brain from a depressogenic preponderance of defensive stress. PMID:25752944

  3. Cue and Target Processing Modulate the Onset of Inhibition of Return

    ERIC Educational Resources Information Center

    Gabay, Shai; Chica, Ana B.; Charras, Pom; Funes, Maria J.; Henik, Avishai

    2012-01-01

    Inhibition of return (IOR) is modulated by task set and appears later in discrimination tasks than in detection tasks. Several hypotheses have been suggested to account for this difference. We tested three of these hypotheses in two experiments by examining the influence of cue and target level of processing on the onset of IOR. In the first…

  4. Effect of low frequency magnetic fields on melanoma: tumor inhibition and immune modulation

    PubMed Central

    2013-01-01

    Background We previously found that the low frequency magnetic fields (LF-MF) inhibited gastric and lung cancer cell growth. We suppose that exposure to LF-MF may modulate immune function so as to inhibit tumor. We here investigated whether LF-MF can inhibit the proliferation and metastasis of melanoma and influence immune function. Methods The effect of MF on the proliferation, cell cycle and ultrastracture of B16-F10 in vitro was detected by cell counting Kit-8 assay, flow cytometry, and transmission electron microscopy. Lung metastasis mice were prepared by injection of 2 × 105 B16-F10 melanoma cells into the tail vein in C57BL/6 mice. The mice were then exposed to an LF-MF (0.4 T, 7.5 Hz) for 43 days. Survival rate, tumor markers and the innate and adaptive immune parameters were measured. Results The growth of B16-F10 cells was inhibited after exposure to the LF-MF. The inhibition was related to induction of cell cycle arrest and decomposition of chromatins. Moreover, the LF-MF prolonged the mouse survival rate and inhibited the proliferation of B16-F10 in melanoma metastasis mice model. Furthermore, the LF-MF modulated the immune response via regulation of immune cells and cytokine production. In addition, the number of Treg cells was decreased in mice with the LF-MF exposure, while the numbers of T cells as well as dendritic cells were significantly increased. Conclusion LF-MF inhibited the growth and metastasis of melanoma cancer cells and improved immune function of tumor-bearing mice. This suggests that the inhibition may be attributed to modulation of LF-MF on immune function and LF-MF may be a potential therapy for treatment of melanoma. PMID:24314291

  5. Selective serotonin reuptake inhibition modulates response inhibition in Parkinson’s disease

    PubMed Central

    Ye, Zheng; Altena, Ellemarije; Nombela, Cristina; Housden, Charlotte R.; Maxwell, Helen; Rittman, Timothy; Huddleston, Chelan; Rae, Charlotte L.; Regenthal, Ralf; Sahakian, Barbara J.; Barker, Roger A.; Robbins, Trevor W.

    2014-01-01

    Impulsivity is common in Parkinson’s disease even in the absence of impulse control disorders. It is likely to be multifactorial, including a dopaminergic ‘overdose’ and structural changes in the frontostriatal circuits for motor control. In addition, we proposed that changes in serotonergic projections to the forebrain also contribute to response inhibition in Parkinson’s disease, based on preclinical animal and human studies. We therefore examined whether the selective serotonin reuptake inhibitor citalopram improves response inhibition, in terms of both behaviour and the efficiency of underlying neural mechanisms. This multimodal magnetic resonance imaging study used a double-blind randomized placebo-controlled crossover design with an integrated Stop-Signal and NoGo paradigm. Twenty-one patients with idiopathic Parkinson’s disease (46–76 years old, 11 male, Hoehn and Yahr stage 1.5–3) received 30 mg citalopram or placebo in addition to their usual dopaminergic medication in two separate sessions. Twenty matched healthy control subjects (54–74 years old, 12 male) were tested without medication. The effects of disease and drug on behavioural performance and regional brain activity were analysed using general linear models. In addition, anatomical connectivity was examined using diffusion tensor imaging and tract-based spatial statistics. We confirmed that Parkinson’s disease caused impairment in response inhibition, with longer Stop-Signal Reaction Time and more NoGo errors under placebo compared with controls, without affecting Go reaction times. This was associated with less stop-specific activation in the right inferior frontal cortex, but no significant difference in NoGo-related activation. Although there was no beneficial main effect of citalopram, it reduced Stop-Signal Reaction Time and NoGo errors, and enhanced inferior frontal activation, in patients with relatively more severe disease (higher Unified Parkinson’s Disease Rating Scale

  6. Demethoxycurcumin modulates human P-glycoprotein function via uncompetitive inhibition of ATPase hydrolysis activity.

    PubMed

    Teng, Yu-Ning; Hsieh, Yow-Wen; Hung, Chin-Chuan; Lin, Hui-Yi

    2015-01-28

    Curcuminoids are major components of Curcuma longa L., which is widely used as spice in food. This study aimed at identifying whether curcumin, demethoxycurcumin, and bisdemethoxycurcumin could modulate efflux function of human P-glycoprotein and be used as chemosensitizers in cancer treatments. Without altering P-glycoprotein expression levels and conformation, the purified curcuminoids significantly inhibited P-glycoprotein efflux function. In rhodamine 123 efflux and calcein-AM accumulation assays, demethoxycurcumin demonstrated the highest inhibition potency (inhibitory IC50 = 1.56 ± 0.13 μM) among the purified curcuminoids, as well as in the fold of reversal assays. Demethoxycurcumin inhibited P-glycoprotein-mediated ATP hydrolysis under concentrations of <1 μM and efficiently inhibited 200 μM verapamil-stimulated ATPase activity, indicating a high affinity of demethoxycurcumin for P-glycoprotein. These results suggested that demethoxycurcumin may be a potential additive natural product in combination with chemotherapeutic agents in drug-resistant cancers.

  7. Allosteric modulation of sigma-1 receptors by SKF83959 inhibits microglia-mediated inflammation.

    PubMed

    Wu, Zhuang; Li, Linlang; Zheng, Long-Tai; Xu, Zhihong; Guo, Lin; Zhen, Xuechu

    2015-09-01

    Recent studies have shown that sigma-1 receptor orthodox agonists can inhibit neuroinflammation. SKF83959 (3-methyl-6-chloro-7,8-hydroxy-1-[3-methylphenyl]-2,3,4,5-tetrahydro-1H-3-benzazepine), an atypical dopamine receptor-1 agonist, has been recently identified as a potent allosteric modulator of sigma-1 receptor. Here, we investigated the anti-inflammatory effects of SKF83959 in lipopolysaccharide (LPS)-stimulated BV2 microglia. Our results indicated that SKF83959 significantly suppressed the expression/release of the pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS), and inhibited the generation of reactive oxygen species. All of these responses were blocked by selective sigma-1 receptor antagonists (BD1047 or BD1063) and by ketoconazole (an inhibitor of enzyme cytochrome c17 to inhibit the synthesis of endogenous dehydroepiandrosterone, DHEA). Additionally, we found that SKF83959 promoted the binding activity of DHEA with sigma-1 receptors, and enhanced the inhibitory effects of DHEA on LPS-induced microglia activation in a synergic manner. Furthermore, in a microglia-conditioned media system, SKF83959 inhibited the cytotoxicity of conditioned medium generated by LPS-activated microglia toward HT-22 neuroblastoma cells. Taken together, our study provides the first evidence that allosteric modulation of sigma-1 receptors by SKF83959 inhibits microglia-mediated inflammation. SKF83959 is a potent allosteric modulator of sigma-1 receptor. Our results indicated that SKF83959 enhanced the activity of endogenous dehydroepiandrosterone (DHEA) in a synergic manner, and inhibited the activation of BV2 microglia and the expression/release of the pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS).

  8. Neuropeptides function in a homeostatic manner to modulate excitation-inhibition imbalance in C. elegans.

    PubMed

    Stawicki, Tamara M; Takayanagi-Kiya, Seika; Zhou, Keming; Jin, Yishi

    2013-05-01

    Neuropeptides play crucial roles in modulating neuronal networks, including changing intrinsic properties of neurons and synaptic efficacy. We previously reported a Caenorhabditis elegans mutant, acr-2(gf), that displays spontaneous convulsions as the result of a gain-of-function mutation in a neuronal nicotinic acetylcholine receptor subunit. The ACR-2 channel is expressed in the cholinergic motor neurons, and acr-2(gf) causes cholinergic overexcitation accompanied by reduced GABAergic inhibition in the locomotor circuit. Here we show that neuropeptides play a homeostatic role that compensates for this excitation-inhibition imbalance in the locomotor circuit. Loss of function in genes required for neuropeptide processing or release of dense core vesicles specifically modulate the convulsion frequency of acr-2(gf). The proprotein convertase EGL-3 is required in the cholinergic motor neurons to restrain convulsions. Electrophysiological recordings of neuromuscular junctions show that loss of egl-3 in acr-2(gf) causes a further reduction of GABAergic inhibition. We identify two neuropeptide encoding genes, flp-1 and flp-18, that together counteract the excitation-inhibition imbalance in acr-2(gf) mutants. We further find that acr-2(gf) causes an increased expression of flp-18 in the ventral cord cholinergic motor neurons and that overexpression of flp-18 reduces the convulsion of acr-2(gf) mutants. The effects of these peptides are in part mediated by two G-protein coupled receptors, NPR-1 and NPR-5. Our data suggest that the chronic overexcitation of the cholinergic motor neurons imposed by acr-2(gf) leads to an increased production of FMRFamide neuropeptides, which act to decrease the activity level of the locomotor circuit, thereby homeostatically modulating the excitation and inhibition imbalance.

  9. Cutaneous afferent input does not modulate motor intracortical inhibition in ageing men.

    PubMed

    Smith, Ashleigh E; Ridding, Michael C; Higgins, Ryan D; Wittert, Gary A; Pitcher, Julia B

    2011-11-01

    Afferent input has been shown to be a powerful modulator of cortical inhibition. Such modulation is likely to be important for the control of ongoing movement, but may also play a role in facilitating neuroplastic reorganisation. Human motor control and neuroplasticity both decline with ageing, whereas the efficacy of short-interval intracortical inhibition (SICI) appears not to. We examined if ageing alters the efficacy of afferent modulation of SICI. Previously, electrical cutaneous stimulation of a finger has been shown to reduce SICI in the motor cortices of young adults. Paired-pulse transcranial magnetic stimulation was used to assess SICI in the cortical representation of the first dorsal interosseous muscle. SICI was assessed separately under two conditions: with and without prior afferent input from electrical cutaneous stimulation of the index finger. Fifteen 'young' (20.1 ± 2.1 years) and 15 'old' male humans (65.5 ± 3.9 years) were studied. SICI did not differ when young and old males were compared. However, when preceded by electrical cutaneous finger stimulation, SICI was reduced in young men but not old men. Reflex testing indicated preservation of the afferent volley to the cortex. These findings suggest that a contributing factor in the decline of motor function, and possibly neuroplasticity, with ageing is loss of SICI modulation, probably due to altered cortical sensorimotor integration of afferent input.

  10. GABAergic and glycinergic inhibition modulate monaural auditory response properties in the avian superior olivary nucleus.

    PubMed

    Coleman, W L; Fischl, M J; Weimann, S R; Burger, R M

    2011-05-01

    The superior olivary nucleus (SON) is the primary source of inhibition in the avian auditory brainstem. While much is known about the role of inhibition at the SON's target nuclei, little is known about how the SON itself processes auditory information or how inhibition modulates these properties. Additionally, the synaptic physiology of inhibitory inputs within the SON has not been described. We investigated these questions using in vivo and in vitro electrophysiological techniques in combination with immunohistochemistry in the chicken, an organism for which the auditory brainstem has otherwise been well characterized. We provide a thorough characterization of monaural response properties in the SON and the influence of inhibitory input in shaping these features. We found that the SON contains a heterogeneous mixture of response patterns to acoustic stimulation and that in most neurons these responses are modulated by both GABAergic and glycinergic inhibitory inputs. Interestingly, many SON neurons tuned to low frequencies have robust phase-locking capability and the precision of this phase locking is enhanced by inhibitory inputs. On the synaptic level, we found that evoked and spontaneous inhibitory postsynaptic currents (IPSCs) within the SON are also mediated by both GABAergic and glycinergic inhibition in all neurons tested. Analysis of spontaneous IPSCs suggests that most SON cells receive a mixture of both purely GABAergic terminals, as well as terminals from which GABA and glycine are coreleased. Evidence for glycinergic signaling within the SON is a novel result that has important implications for understanding inhibitory function in the auditory brainstem.

  11. Genomic agonism and phenotypic antagonism between estrogen and progesterone receptors in breast cancer

    PubMed Central

    Singhal, Hari; Greene, Marianne E.; Tarulli, Gerard; Zarnke, Allison L.; Bourgo, Ryan J.; Laine, Muriel; Chang, Ya-Fang; Ma, Shihong; Dembo, Anna G.; Raj, Ganesh V.; Hickey, Theresa E.; Tilley, Wayne D.; Greene, Geoffrey L.

    2016-01-01

    The functional role of progesterone receptor (PR) and its impact on estrogen signaling in breast cancer remain controversial. In primary ER+ (estrogen receptor–positive)/PR+ human tumors, we report that PR reprograms estrogen signaling as a genomic agonist and a phenotypic antagonist. In isolation, estrogen and progestin act as genomic agonists by regulating the expression of common target genes in similar directions, but at different levels. Similarly, in isolation, progestin is also a weak phenotypic agonist of estrogen action. However, in the presence of both hormones, progestin behaves as a phenotypic estrogen antagonist. PR remodels nucleosomes to noncompetitively redirect ER genomic binding to distal enhancers enriched for BRCA1 binding motifs and sites that link PR and ER/PR complexes. When both hormones are present, progestin modulates estrogen action, such that responsive transcriptomes, cellular processes, and ER/PR recruitment to genomic sites correlate with those observed with PR alone, but not ER alone. Despite this overall correlation, the transcriptome patterns modulated by dual treatment are sufficiently different from individual treatments, such that antagonism of oncogenic processes is both predicted and observed. Combination therapies using the selective PR modulator/antagonist (SPRM) CDB4124 in combination with tamoxifen elicited 70% cytotoxic tumor regression of T47D tumor xenografts, whereas individual therapies inhibited tumor growth without net regression. Our findings demonstrate that PR redirects ER chromatin binding to antagonize estrogen signaling and that SPRMs can potentiate responses to antiestrogens, suggesting that cotargeting of ER and PR in ER+/PR+ breast cancers should be explored. PMID:27386569

  12. Genomic agonism and phenotypic antagonism between estrogen and progesterone receptors in breast cancer.

    PubMed

    Singhal, Hari; Greene, Marianne E; Tarulli, Gerard; Zarnke, Allison L; Bourgo, Ryan J; Laine, Muriel; Chang, Ya-Fang; Ma, Shihong; Dembo, Anna G; Raj, Ganesh V; Hickey, Theresa E; Tilley, Wayne D; Greene, Geoffrey L

    2016-06-01

    The functional role of progesterone receptor (PR) and its impact on estrogen signaling in breast cancer remain controversial. In primary ER(+) (estrogen receptor-positive)/PR(+) human tumors, we report that PR reprograms estrogen signaling as a genomic agonist and a phenotypic antagonist. In isolation, estrogen and progestin act as genomic agonists by regulating the expression of common target genes in similar directions, but at different levels. Similarly, in isolation, progestin is also a weak phenotypic agonist of estrogen action. However, in the presence of both hormones, progestin behaves as a phenotypic estrogen antagonist. PR remodels nucleosomes to noncompetitively redirect ER genomic binding to distal enhancers enriched for BRCA1 binding motifs and sites that link PR and ER/PR complexes. When both hormones are present, progestin modulates estrogen action, such that responsive transcriptomes, cellular processes, and ER/PR recruitment to genomic sites correlate with those observed with PR alone, but not ER alone. Despite this overall correlation, the transcriptome patterns modulated by dual treatment are sufficiently different from individual treatments, such that antagonism of oncogenic processes is both predicted and observed. Combination therapies using the selective PR modulator/antagonist (SPRM) CDB4124 in combination with tamoxifen elicited 70% cytotoxic tumor regression of T47D tumor xenografts, whereas individual therapies inhibited tumor growth without net regression. Our findings demonstrate that PR redirects ER chromatin binding to antagonize estrogen signaling and that SPRMs can potentiate responses to antiestrogens, suggesting that cotargeting of ER and PR in ER(+)/PR(+) breast cancers should be explored. PMID:27386569

  13. Modulation of contact system proteases by glycosaminoglycans. Selective enhancement of the inhibition of factor XIa.

    PubMed

    Wuillemin, W A; Eldering, E; Citarella, F; de Ruig, C P; ten Cate, H; Hack, C E

    1996-05-31

    We investigated the influence of dextran sulfate, heparin, heparan sulfate, and dermatan sulfate on the inhibition of FXIa (where FXIa is activated factor XI, for example), FXIIa, and kallikrein by C1 inhibitor, alpha1-antitrypsin, alpha2-antiplasmin, and antithrombin III. The second-order rate constants for the inhibition of FXIa by C1 inhibitor, alpha1-antitrypsin, alpha2-antiplasmin, and antithrombin III, in the absence of glycosaminoglycans, were 1.8, 0.1, 0.43, and 0.32 x 10(3) M-1 s-1, respectively. The rate constants of the inactivation of FXIa by C1 inhibitor and by antithrombin III increased up to 117-fold in the presence of glycosaminoglycans. These data predicted that considering the plasma concentration of the inhibitors, C1 inhibitor would be the main inhibitor of FXIa in plasma in the presence of glycosaminoglycans. Results of experiments in which the formation of complexes between serine protease inhibitors and FXIa was studied in plasma agreed with this prediction. Glycosaminoglycans did not enhance the inhibition of alpha-FXIIa, beta-FXIIa, or kallikrein by C1 inhibitor. Thus, physiological glycosaminoglycans selectively enhance inhibition of FXIa without affecting the activity of FXIIa and kallikrein, suggesting that glycosaminoglycans may modulate the biological effects of contact activation, by inhibiting intrinsic coagulation without affecting the fibrinolytic potential of FXIIa/kallikrein.

  14. Fucoidan, a Sulfated Polysaccharide, Inhibits Osteoclast Differentiation and Function by Modulating RANKL Signaling

    PubMed Central

    Kim, Young Woo; Baek, Seung-Hoon; Lee, Sang-Han; Kim, Tae-Ho; Kim, Shin-Yoon

    2014-01-01

    Multinucleated osteoclasts differentiate from hematopoietic progenitors of the monocyte/macrophage lineage. Because of its pivotal role in bone resorption, regulation of osteoclast differentiation is a potential therapeutic approach to the treatment of erosive bone disease. In this study, we have found that fucoidan, a sulfated polysaccharide extracted from brown seaweed, inhibited osteoclast differentiation. In particular, addition of fucoidan into the early stage osteoclast cultures significantly inhibited receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL)-induced osteoclast formation, thus suggesting that fucoidan affects osteoclast progenitors. Furthermore, fucoidan significantly inhibited the activation of RANKL-dependent mitogen-activated protein kinases (MAPKs) such as JNK, ERK, and p38, and also c-Fos and NFATc1, which are crucial transcription factors for osteoclastogenesis. In addition, the activation of NF-κB, which is an upstream transcription factor modulating NFATc1 expression, was alleviated in the fucoidan-treated cells. These results collectively suggest that fucoidan inhibits osteoclastogenesis from bone marrow macrophages by inhibiting RANKL-induced p38, JNK, ERK and NF-κB activation, and by downregulating the expression of genes that partake in both osteoclast differentiation and resorption. PMID:25334060

  15. 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

  16. Aerobic exercise modulates intracortical inhibition and facilitation in a nonexercised upper limb muscle

    PubMed Central

    2014-01-01

    Background Despite growing interest in the relationship between exercise and short-term neural plasticity, the effects of exercise on motor cortical (M1) excitability are not well studied. Acute, lower-limb aerobic exercise may potentially modulate M1 excitability in working muscles, but the effects on muscles not involved in the exercise are unknown. Here we examined the excitability changes in an upper limb muscle representation following a single session of lower body aerobic exercise. Investigating the response to exercise in a non-exercised muscle may help to determine the clinical usefulness of lower-body exercise interventions for upper limb neurorehabilitation. Methods In this study, transcranial magnetic stimulation was used to assess input–output curves, short-interval intracortical inhibition (SICI), long-interval intracortical inhibition (LICI) and intracortical facilitation (ICF) in the extensor carpi radialis muscle in twelve healthy individuals following a single session of moderate stationary biking. Additionally, we examined whether the presence of a common polymorphism of the brain-derived neurotrophic factor (BDNF) gene would affect the response of these measures to exercise. Results We observed significant increases in ICF and decreases in SICI following exercise. No changes in LICI were detected, and no differences were observed in input–output curves following exercise, or between BDNF groups. Conclusions The current results demonstrate that the modulation of intracortical excitability following aerobic exercise is not limited to those muscles involved in the exercise, and that while exercise does not directly modulate the excitability of motor neurons, it may facilitate the induction of experience-dependent plasticity via a decrease in intracortical inhibition and increase in intracortical facilitation. These findings indicate that exercise may create favourable conditions for adaptive plasticity in M1 and may be an effective adjunct to

  17. Startle response and prepulse inhibition modulation by positive- and negative-induced affect.

    PubMed

    De la Casa, Luis Gonzalo; Mena, Auxiliadora; Puentes, Andrea

    2014-02-01

    The startle response, a set of reflex behaviours intended to prepare the organism to face a potentially threatening stimulus, can be modulated by several factors as, for example, changes in affective state, or previous presentation of a weak stimulus (a phenomenon termed Pre-Pulse Inhibition [PPI]). In this paper we analyse whether the induction of positive or negative affective states in the participants modulates the startle response and the PPI phenomenon. The results revealed a decrease of the startle response and an increase of the PPI effect when registered while the participants were exposed to pleasant images (Experiment 1), and an increase of the startle response and of the PPI effect when they were exposed to a video-clip of unpleasant content (Experiment 2). These data are interpreted considering that changes in affective states correlate with changes in the startle reflex intensity, but changes in PPI might be the result of an attentional process.

  18. Startle response and prepulse inhibition modulation by positive- and negative-induced affect.

    PubMed

    De la Casa, Luis Gonzalo; Mena, Auxiliadora; Puentes, Andrea

    2014-02-01

    The startle response, a set of reflex behaviours intended to prepare the organism to face a potentially threatening stimulus, can be modulated by several factors as, for example, changes in affective state, or previous presentation of a weak stimulus (a phenomenon termed Pre-Pulse Inhibition [PPI]). In this paper we analyse whether the induction of positive or negative affective states in the participants modulates the startle response and the PPI phenomenon. The results revealed a decrease of the startle response and an increase of the PPI effect when registered while the participants were exposed to pleasant images (Experiment 1), and an increase of the startle response and of the PPI effect when they were exposed to a video-clip of unpleasant content (Experiment 2). These data are interpreted considering that changes in affective states correlate with changes in the startle reflex intensity, but changes in PPI might be the result of an attentional process. PMID:24188916

  19. Tonic synaptic inhibition modulates neuronal output pattern and spatiotemporal synaptic integration.

    PubMed

    Häusser, M; Clark, B A

    1997-09-01

    Irregular firing patterns are observed in most central neurons in vivo, but their origin is controversial. Here, we show that two types of inhibitory neurons in the cerebellar cortex fire spontaneously and regularly in the absence of synaptic input but generate an irregular firing pattern in the presence of tonic synaptic inhibition. Paired recordings between synaptically connected neurons revealed that single action potentials in inhibitory interneurons cause highly variable delays in action potential firing in their postsynaptic cells. Activity in single and multiple inhibitory interneurons also significantly reduces postsynaptic membrane time constant and input resistance. These findings suggest that the time window for synaptic integration is a dynamic variable modulated by the level of tonic inhibition, and that rate coding and temporal coding strategies may be used in parallel in the same cell type. PMID:9331356

  20. Osthole inhibits histamine-dependent itch via modulating TRPV1 activity

    PubMed Central

    Yang, Niu-Niu; Shi, Hao; Yu, Guang; Wang, Chang-Ming; Zhu, Chan; Yang, Yan; Yuan, Xiao-Lin; Tang, Min; Wang, Zhong-li; Gegen, Tana; He, Qian; Tang, Kehua; Lan, Lei; Wu, Guan-Yi; Tang, Zong-Xiang

    2016-01-01

    Osthole, an active coumarin isolated from Cnidium monnieri (L.) Cusson, has long been used in China as an antipruritic herbal medicine; however, the antipruitic mechanism of osthole is unknown. We studied the molecular mechanism of osthole in histamine-dependent itch by behavioral test, Ca2+ imaging, and electrophysiological experiments. First, osthole clearly remitted the scratching behaviors of mice induced with histamine, HTMT, and VUF8430. Second, in cultured dorsal root ganglion (DRG) neurons, osthole showed a dose-dependent inhibitory effect to histamine. On the same neurons, osthole also decreased the response to capsaicin and histamine. In further tests, the capsaicin-induced inward currents were inhibited by osthole. These results revealed that osthole inhibited histamine-dependent itch by modulating TRPV1 activity. This study will be helpful in understanding how osthole exerts anti-pruritus effects and suggests that osthole may be a useful treatment medicine for histamine-dependent itch. PMID:27160770

  1. A small molecule modulates Jumonji histone demethylase activity and selectively inhibits cancer growth

    PubMed Central

    Wang, Lei; Chang, Jianjun; Varghese, Diana; Dellinger, Michael; Kumar, Subodh; Best, Anne M.; Ruiz, Julio; Bruick, Richard; Peña-Llopis, Samuel; Xu, Junjie; Babinski, David J.; Frantz, Doug E.; Brekken, Rolf A.; Quinn, Amy M.; Simeonov, Anton; Easmon, Johnny; Martinez, Elisabeth D.

    2013-01-01

    The pharmacological inhibition of general transcriptional regulators has the potential to block growth through targeting multiple tumorigenic signaling pathways simultaneously. Here, using an innovative cell-based screen, we identify a structurally unique small molecule (named JIB-04) which specifically inhibits the activity of the Jumonji family of histone demethylases in vitro, in cancer cells, and in tumors in vivo. Unlike known inhibitors, JIB-04 is not a competitive inhibitor of α-ketoglutarate. In cancer but not in patient-matched normal cells, JIB-04 alters a subset of transcriptional pathways and blocks viability. In mice, JIB-04 reduces tumor burden and prolongs survival. Importantly, we find that patients with breast tumors that overexpress Jumonji demethylases have significantly lower survival. Thus JIB-04, a novel inhibitor of Jumonji demethylases in vitro and in vivo, constitutes a unique potential therapeutic and research tool against cancer, and validates the use of unbiased cellular screens to discover chemical modulators with disease relevance. PMID:23792809

  2. Plumbagin inhibits breast tumor bone metastasis and osteolysis by modulating the tumor-bone microenvironment.

    PubMed

    Li, Z; Xiao, J; Wu, X; Li, W; Yang, Z; Xie, J; Xu, L; Cai, X; Lin, Z; Guo, W; Luo, J; Liu, M

    2012-09-01

    Bone metastasis is a common and serious consequence of breast cancer. Bidirectional interaction between tumor cells and the bone marrow microenvironment drives a so-called 'vicious cycle' that promotes tumor cell malignancy and stimulates osteolysis. Targeting these interactions and pathways in the tumor-bone microenvironment has been an encouraging strategy for bone metastasis therapy. In the present study, we examined the effects of plumbagin on breast cancer bone metastasis. Our data indicated that plumbagin inhibited cancer cell migration and invasion, suppressed the expression of osteoclast-activating factors, altered the cancer cell induced RANKL/OPG ratio in osteoblasts, and blocked both cancer cell- and RANKL-stimulated osteoclastogenesis. In mouse model of bone metastasis, we further demonstrated that plumbagin significantly repressed breast cancer cell metastasis and osteolysis, inhibited cancer cell induced-osteoclastogenesis and the secretion of osteoclast-activating factors in vivo. At the molecular level, we found that plumbagin abrogated RANKL-induced NF-κB and MAPK pathways by blocking RANK association with TRAF6 in osteoclastogenesis, and by inhibiting the expression of osteoclast-activating factors through the suppression of NF-κB activity in breast cancer cells. Taken together, our data demonstrate that plumbagin inhibits breast tumor bone metastasis and osteolysis by modulating the tumor-bone microenvironment and that plumbagin may serve as a novel agent in the treatment of tumor bone metastasis.

  3. How Does Emotional Context Modulate Response Inhibition in Alexithymia: Electrophysiological Evidence from an ERP Study

    PubMed Central

    Yu, Fengqiong; Cao, Zhaolun; Zhu, Chunyan; Cai, Zhu; Hu, Panpan; Pu, Hui; Wang, Kai

    2012-01-01

    Background Alexithymia, characterized by difficulties in identifying and describing feelings, is highly indicative of a broad range of psychiatric disorders. Several studies have also discovered the response inhibition ability impairment in alexithymia. However, few studies on alexithymic individuals have specifically examined how emotional context modulates response inhibition procedure. In order to investigate emotion cognition interaction in alexithymia, we analyzed the spatiao-temporal features of such emotional response inhibition by the approaches of event-related potentials and neural source-localization. Method The study participants included 15 subjects with high alexithymia scores on the 20-item Toronto Alexithymia Scale (alexithymic group) and 15 matched subjects with low alexithymia scores (control group). Subjects were instructed to perform a modified emotional Go/Nogo task while their continuous electroencephalography activities were synchronously recorded. The task includes 3 categories of emotional contexts (positive, negative and neutral) and 2 letters (“M” and “W”) centered in the screen. Participants were told to complete go and nogo actions based on the letters. We tested the influence of alexithymia in this emotional Go/Nogo task both in behavioral level and related neural activities of N2 and P3 ERP components. Results We found that negatively valenced context elicited larger central P3 amplitudes of the Nogo–Go difference wave in the alexithymic group than in the control group. Furthermore, source-localization analyses implicated the anterior cingulate cortex (ACC) as the neural generator of the Nogo-P3. Conclusion These findings suggest that difficulties in identifying feelings, particularly in negative emotions, is a major feature of alexithymia, and the ACC plays a critical role in emotion-modulated response inhibition related to alexithymia. PMID:23227242

  4. Modulation of spike and burst rate in a minimal neuronal circuit with feed-forward inhibition.

    PubMed

    Zeldenrust, Fleur; Wadman, Wytse J

    2013-04-01

    effective and introduces spike-spike interactions at a 40-140 ms time scale. Feed-forward inhibition always decreases the burst firing rate, but the effects on the single spike rate depended on the spatiotemporal organization of inhibition. Therefore, using different connection strategies, the spike and burst rate of such a minimal circuit can be modulated independently.

  5. HDAC Inhibition Modulates Cardiac PPARs and Fatty Acid Metabolism in Diabetic Cardiomyopathy.

    PubMed

    Lee, Ting-I; Kao, Yu-Hsun; Tsai, Wen-Chin; Chung, Cheng-Chih; Chen, Yao-Chang; Chen, Yi-Jen

    2016-01-01

    Peroxisome proliferator-activated receptors (PPARs) regulate cardiac glucose and lipid homeostasis. Histone deacetylase (HDAC) inhibitor has anti-inflammatory effects which may play a key role in modulating PPARs and fatty acid metabolism. The aim of this study was to investigate whether HDAC inhibitor, MPT0E014, can modulate myocardial PPARs, inflammation, and fatty acid metabolism in diabetes mellitus (DM) cardiomyopathy. Electrocardiography, echocardiography, and western blotting were used to evaluate the electrophysiological activity, cardiac structure, fatty acid metabolism, inflammation, and PPAR isoform expressions in the control and streptozotocin-nicotinamide-induced DM rats with or without MPT0E014. Compared to control, DM and MPT0E014-treated DM rats had elevated blood glucose levels and lower body weights. However, MPT0E014-treated DM and control rats had smaller left ventricular end-diastolic diameter and shorter QT interval than DM rats. The control and MPT0E014-treated DM rats had greater cardiac PPAR-α and PPAR-δ protein expressions, but less cardiac PPAR-γ than DM rats. Moreover, control and MPT0E014-treated DM rats had lower concentrations of 5' adenosine monophosphate-activated protein kinase 2α, PPAR-γ coactivator 1α, phosphorylated acetyl CoA carboxylase, cluster of differentiation 36, diacylglycerol acyltransferase 1 (DGAT1), DGAT2, tumor necrosis factor-α, and interleukin-6 protein than DM rats. HDAC inhibition significantly attenuated DM cardiomyopathy through modulation of cardiac PPARS, fatty acid metabolism, and proinflammatory cytokines. PMID:27446205

  6. Modulating behavioral inhibition by tDCS combined with cognitive training.

    PubMed

    Ditye, Thomas; Jacobson, Liron; Walsh, Vincent; Lavidor, Michal

    2012-06-01

    Cognitive training is an effective tool to improve a variety of cognitive functions, and a small number of studies have now shown that brain stimulation accompanying these training protocols can enhance their effects. In the domain of behavioral inhibition, little is known about how training can affect this skill. As for transcranial direct current stimulation (tDCS), it was previously found that stimulation over the right inferior frontal gyrus (rIFG) facilitates behavioral inhibition performance and modulates its electrophysiological correlates. This study aimed to investigate this behavioral facilitation in the context of a learning paradigm by giving tDCS over rIFG repetitively over four consecutive days of training on a behavioral inhibition task (stop signal task (SST)). Twenty-two participants took part; ten participants were assigned to receive anodal tDCS (1.5 mA, 15 min), 12 were assigned to receive training but not active stimulation. There was a significant effect of training on learning and performance in the SST, and the integration of the training and rIFG-tDCS produced a more linear learning slope. Better performance was also found in the active stimulation group. Our findings show that tDCS-combined cognitive training is an effective tool for improving the ability to inhibit responses. The current study could constitute a step toward the use of tDCS and cognitive training as a therapeutic tool for cognitive control impairments in conditions such as attention-deficit hyperactivity disorder (ADHD) or schizophrenia. PMID:22532165

  7. Iron inhibits activation-induced cytidine deaminase enzymatic activity and modulates immunoglobulin class switch DNA recombination.

    PubMed

    Li, Guideng; Pone, Egest J; Tran, Daniel C; Patel, Pina J; Dao, Lisa; Xu, Zhenming; Casali, Paolo

    2012-06-15

    Immunoglobulin (Ig) class switch DNA recombination (CSR) and somatic hypermutation (SHM) are critical for the maturation of the antibody response. Activation-induced cytidine deaminase (AID) initiates CSR and SHM by deaminating deoxycytidines (dCs) in switch (S) and V(D)J region DNA, respectively, to generate deoxyuracils (dUs). Processing of dUs by uracil DNA glycosylase (UNG) yields abasic sites, which are excised by apurinic/apyrimidinic endonucleases, eventually generating double strand DNA breaks, the obligatory intermediates of CSR. Here, we found that the bivalent iron ion (Fe(2+), ferrous) suppressed CSR, leading to decreased number of switched B cells, decreased postrecombination Iμ-C(H) transcripts, and reduced titers of secreted class-switched IgG1, IgG3, and IgA antibodies, without alterations in critical CSR factors, such as AID, 14-3-3γ, or PTIP, or in general germline I(H)-S-C(H) transcription. Fe(2+) did not affect B cell proliferation or plasmacytoid differentiation. Rather, it inhibited AID-mediated dC deamination in a dose-dependent fashion. The inhibition of intrinsic AID enzymatic activity by Fe(2+) was specific, as shown by lack of inhibition of AID-mediated dC deamination by other bivalent metal ions, such as Zn(2+), Mn(2+), Mg(2+), or Ni(2+), and the inability of Fe(2+) to inhibit UNG-mediated dU excision. Overall, our findings have outlined a novel role of iron in modulating a B cell differentiation process that is critical to the generation of effective antibody responses to microbial pathogens and tumoral cells. They also suggest a possible role of iron in dampening AID-dependent autoimmunity and neoplastic transformation.

  8. Pedilanthus tithymaloides Inhibits HSV Infection by Modulating NF-κB Signaling

    PubMed Central

    Ojha, Durbadal; Das, Rashmi; Sobia, Parveen; Dwivedi, Vedprakash; Ghosh, Soma; Samanta, Amalesh; Chattopadhyay, Debprasad

    2015-01-01

    Pedilanthus tithymaloides (PT), a widely used ethnomedicinal plant, has been employed to treat a number of skin conditions. To extend its utility and to fully exploit its medicinal potential, we have evaluated the in vitro antiviral activity of a methanolic extract of PT leaves and its isolated compounds against Herpes Simplex Virus type 2 (HSV-2). Bioactivity-guided studies revealed that the extract and one of its constituents, luteolin, had potent antiviral activity against wild-type and clinical isolates of HSV-2 (EC50 48.5–52.6 and 22.4–27.5 μg/ml, respectively), with nearly complete inhibition at 86.5–101.8 and 40.2–49.6 μg/ml, respectively. The inhibitory effect was significant (p<0.001) when the drug was added 2 h prior to infection, and was effective up to 4 h post-infection. As viral replication requires NF-κB activation, we examined whether the observed extract-induced inhibition of HSV-2 was related to NF-κB inhibition. Interestingly, we observed that treatment of HSV-2-infected cells with extract or luteolin suppressed NF-κB activation. Although NF-κB, JNK and MAPK activation was compromised during HSV replication, neither the extract nor luteolin affected HSV-2-induced JNK1/2 and MAPK activation. Moreover, the PT leaf extract and luteolin potently down-regulated the expression of tumor necrosis factor (TNF)-α, Interleukin (IL)-1β, IL-6, NO and iNOS and the production of gamma interferon (IFN-γ), which are directly involved in controlling the NF-κB signaling pathway. Thus, our results indicate that both PT leaf extract and luteolin modulate the NF-κB signaling pathway, resulting in the inhibition of HSV-2 replication. PMID:26405764

  9. Modulation of interhemispheric inhibition by volitional motor activity: an ipsilateral silent period study.

    PubMed

    Giovannelli, Fabio; Borgheresi, Alessandra; Balestrieri, Fabrizio; Zaccara, Gaetano; Viggiano, Maria Pia; Cincotta, Massimo; Ziemann, Ulf

    2009-11-15

    Brief interruption of voluntary EMG in a hand muscle by focal transcranial magnetic stimulation (TMS) of the ipsilateral primary motor cortex (M1), the so-called ipsilateral silent period (ISP), is a measure of interhemispheric motor inhibition. However, little is known about how volitional motor activity would modulate the ISP. Here we tested in 30 healthy adults to what extent and under what conditions voluntary activation of the stimulated right M1 by moving the left hand strengthens interhemispheric inhibition as indexed by an enhancement of the ISP area in the maximally contracting right first dorsal interosseous (FDI). Left index finger abduction, already at low levels of contraction, significantly enhanced the ISP compared to left hand at rest. Even imagination of left index finger movement enhanced the ISP compared to rest or mental calculation. This enhancement occurred in the absence of motor-evoked potential amplitude modulation in the left FDI, thus excluding a non-specific contribution from an increase in right M1 corticospinal excitability. Contraction of the left extensor indicis, but not contraction of more proximal left upper limb or left or right lower limb muscles also enhanced the ISP. A reaction time experiment showed that the ISP enhancement developed at a late stage of movement preparation just before or at movement onset. Interhemispheric inhibition of the motor-evoked potential as tested by a bifocal paired-pulse TMS protocol and thought to be mediated via a neuronal circuit different to the ISP was not enhanced when tested under identical motor task conditions. Finally, ISP enhancement by contraction of the left FDI correlated inversely with EMG mirror activity in the right FDI during phasic abductions of the left index finger. Our findings strongly suggest that voluntary M1 activation by real or imagined movement of the contralateral hand increases interhemispheric motor inhibition of the opposite M1. This phenomenon shows substantial

  10. Short-interval intracortical inhibition is modulated by high-frequency peripheral mixed nerve stimulation.

    PubMed

    Murakami, Takenobu; Sakuma, Kenji; Nomura, Takashi; Nakashima, Kenji

    2007-06-01

    Cortical excitability can be modulated by manipulation of afferent input. We investigated the influence of peripheral mixed nerve stimulation on the excitability of the motor cortex. Motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) in the right abductor pollicis brevis (APB), extensor carpi radialis (ECR) and first dorsal interosseous (FDI) muscles were evaluated using paired-pulse transcranial magnetic stimulation (TMS) before and after high-frequency peripheral mixed nerve stimulation (150 Hz, 30 min) over the right median nerve at the wrist. The MEP amplitude and SICI of the APB muscle decreased transiently 0-10 min after the intervention, whereas the ICF did not change. High-frequency peripheral mixed nerve stimulation reduced the excitability of the motor cortex. The decrement in the SICI, which reflects the function of GABA(A)ergic inhibitory interneurons, might compensate for the reduced motor cortical excitability after high-frequency peripheral mixed nerve stimulation.

  11. Leishmania major lipophosphoglycan modulates the phenotype and inhibits migration of murine Langerhans cells

    PubMed Central

    Ponte-Sucre, Alicia; Heise, Dirk; Moll, Heidrun

    2001-01-01

    Langerhans cells (LC), members of the dendritic cell family, play a central role in the initiation and regulation of the immune response against the protozoan parasite Leishmania major. LC take up antigens in the skin and transport them to the regional lymph nodes for presentation to T cells. However, it is not known whether LC functions are modulated by parasite antigens. In the present study, we examined the effect of a major parasite surface molecule, L. major lipophosphoglycan (LPG), on the maturation of LC and their migratory properties. The results show that exposure to LPG did not affect the expression of major histocompatibility complex (MHC) class II and B7, but induced an up-regulation of CD25, CD31 and vascular endothelial (VE)-cadherin expression and a down-regulation of Mac-1 expression, by LC. Importantly, LPG treatment inhibited the migratory activity of LC, as it reduced their efflux from skin explants and their migration in transwell cultures. These results suggest that Leishmania LPG impairs LC migration out of the skin and thus may modulate their immunostimulatory functions, which require LC translocation from skin to lymph nodes. PMID:11899433

  12. miR-25 modulates NSCLC cell radio-sensitivity through directly inhibiting BTG2 expression

    SciTech Connect

    He, Zhiwei Liu, Yi Xiao, Bing Qian, Xiaosen

    2015-02-13

    A large proportion of the NSCLC patients were insensitive to radiotherapy, but the exact mechanism is still unclear. This study explored the role of miR-25 in regulating sensitivity of NSCLC cells to ionizing radiation (IR) and its downstream targets. Based on measurement in tumor samples from NSCLC patients, this study found that miR-25 expression is upregulated in both NSCLC and radio-resistant NSCLC patients compared the healthy and radio-sensitive controls. In addition, BTG expression was found negatively correlated with miR-25a expression in the both tissues and cells. By applying luciferase reporter assay, we verified two putative binding sites between miR-25 and BTG2. Therefore, BTG2 is a directly target of miR-25 in NSCLC cancer. By applying loss-and-gain function analysis in NSCLC cell lines, we demonstrated that miR-25-BTG2 axis could directly regulated BTG2 expression and affect radiotherapy sensitivity of NSCLC cells. - Highlights: • miR-25 is upregulated, while BTG2 is downregulated in radioresistant NSCLC patients. • miR-25 modulates sensitivity to radiation induced apoptosis. • miR-25 directly targets BTG2 and suppresses its expression. • miR-25 modulates sensitivity to radiotherapy through inhibiting BTG2 expression.

  13. 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

  14. Soluble amyloid precursor protein alpha inhibits tau phosphorylation through modulation of GSK3β signaling pathway.

    PubMed

    Deng, Juan; Habib, Ahsan; Obregon, Demian F; Barger, Steven W; Giunta, Brian; Wang, Yan-Jiang; Hou, Huayan; Sawmiller, Darrell; Tan, Jun

    2015-11-01

    We recently found that sAPPα decreases amyloid-beta generation by directly associating with β-site amyloid precursor protein (APP)-converting enzyme 1 (BACE1), thereby modulating APP processing. Because inhibition of BACE1 decreases glycogen synthase kinase 3 beta (GSK3β)-mediated Alzheimer's disease (AD)-like tau phosphorylation in AD patient-derived neurons, we determined whether sAPPα also reduces GSK3β-mediated tau phosphorylation. We initially found increased levels of inhibitory phosphorylation of GSK3β (Ser9) in primary neurons from sAPPα over-expressing mice. Further, recombinant human sAPPα evoked the same phenomenon in SH-SY5Y cells. Further, in SH-SY5Y cells over-expressing BACE1, and HeLa cells over-expressing human tau, sAPPα reduced GSK3β activity and tau phosphorylation. Importantly, the reductions in GSK3β activity and tau phosphorylation elicited by sAPPα were prevented by BACE1 but not γ-secretase inhibition. In accord, AD mice over-expressing human sAPPα had less GSK3β activity and tau phosphorylation compared with controls. These results implicate a direct relationship between APP β-processing and GSK3β-mediated tau phosphorylation and further define the central role of sAPPα in APP autoregulation and AD pathogenesis. PMID:26342176

  15. Oleanolic acid modulates multiple intracellular targets to inhibit colorectal cancer growth.

    PubMed

    Li, Li; Wei, Lihui; Shen, Aling; Chu, Jianfeng; Lin, Jiumao; Peng, Jun

    2015-12-01

    Due to drug resistance and unacceptable cytotoxicity of most currently-used cancer chemotherapies, naturally occurring products have gained attention in the field of anticancer treatment. Oleanolic acid (OA) is a natural pentacyclic triterpenoic acid and a principal active compound in many medicinal herbs that have long been used to clinically treat various types of human malignancies. Using a colorectal cancer (CRC) mouse xenograft model and the cell line HT-29, we evaluated the effect of OA on tumor growth in vivo and in vitro, and investigated the underlying molecular mechanisms in the present study. We found that OA significantly inhibited tumor growth in volume and weight in CRC xenograft mice. In addition, OA treatment led to the induction of apoptosis and inhibition of cell proliferation. OA significantly reduced the expression of Bcl-2, Cyclin D1 and CKD4, whereas Bax and p21 expression was profoundly increased after OA treatment. Furthermore, OA significantly suppressed the activation of Akt, p70S6K and MAPK signalings, but promoted p53 pathway activation. Collectively, findings from this study suggest that OA possesses a broad range of anticancer effects via modulation of multiple intracellular targets. PMID:26459864

  16. HDAC Inhibition Modulates Cardiac PPARs and Fatty Acid Metabolism in Diabetic Cardiomyopathy

    PubMed Central

    Lee, Ting-I; Tsai, Wen-Chin; Chung, Cheng-Chih; Chen, Yao-Chang; Chen, Yi-Jen

    2016-01-01

    Peroxisome proliferator-activated receptors (PPARs) regulate cardiac glucose and lipid homeostasis. Histone deacetylase (HDAC) inhibitor has anti-inflammatory effects which may play a key role in modulating PPARs and fatty acid metabolism. The aim of this study was to investigate whether HDAC inhibitor, MPT0E014, can modulate myocardial PPARs, inflammation, and fatty acid metabolism in diabetes mellitus (DM) cardiomyopathy. Electrocardiography, echocardiography, and western blotting were used to evaluate the electrophysiological activity, cardiac structure, fatty acid metabolism, inflammation, and PPAR isoform expressions in the control and streptozotocin-nicotinamide-induced DM rats with or without MPT0E014. Compared to control, DM and MPT0E014-treated DM rats had elevated blood glucose levels and lower body weights. However, MPT0E014-treated DM and control rats had smaller left ventricular end-diastolic diameter and shorter QT interval than DM rats. The control and MPT0E014-treated DM rats had greater cardiac PPAR-α and PPAR-δ protein expressions, but less cardiac PPAR-γ than DM rats. Moreover, control and MPT0E014-treated DM rats had lower concentrations of 5′ adenosine monophosphate-activated protein kinase 2α, PPAR-γ coactivator 1α, phosphorylated acetyl CoA carboxylase, cluster of differentiation 36, diacylglycerol acyltransferase 1 (DGAT1), DGAT2, tumor necrosis factor-α, and interleukin-6 protein than DM rats. HDAC inhibition significantly attenuated DM cardiomyopathy through modulation of cardiac PPARS, fatty acid metabolism, and proinflammatory cytokines. PMID:27446205

  17. All-trans-retinoic Acid Modulates the Plasticity and Inhibits the Motility of Breast Cancer Cells

    PubMed Central

    Zanetti, Adriana; Affatato, Roberta; Centritto, Floriana; Fratelli, Maddalena; Kurosaki, Mami; Barzago, Maria Monica; Bolis, Marco; Terao, Mineko; Garattini, Enrico; Paroni, Gabriela

    2015-01-01

    All-trans-retinoic acid (ATRA) is a natural compound proposed for the treatment/chemoprevention of breast cancer. Increasing evidence indicates that aberrant regulation of epithelial-to-mesenchymal transition (EMT) is a determinant of the cancer cell invasive and metastatic behavior. The effects of ATRA on EMT are largely unknown. In HER2-positive SKBR3 and UACC812 cells, showing co-amplification of the ERBB2 and RARA genes, ATRA activates a RARα-dependent epithelial differentiation program. In SKBR3 cells, this causes the formation/reorganization of adherens and tight junctions. Epithelial differentiation and augmented cell-cell contacts underlie the anti-migratory action exerted by the retinoid in cells exposed to the EMT-inducing factors EGF and heregulin-β1. Down-regulation of NOTCH1, an emerging EMT modulator, is involved in the inhibition of motility by ATRA. Indeed, the retinoid blocks NOTCH1 up-regulation by EGF and/or heregulin-β1. Pharmacological inhibition of γ-secretase and NOTCH1 processing also abrogates SKBR3 cell migration. Stimulation of TGFβ contributes to the anti-migratory effect of ATRA. The retinoid switches TGFβ from an EMT-inducing and pro-migratory determinant to an anti-migratory mediator. Inhibition of the NOTCH1 pathway not only plays a role in the anti-migratory action of ATRA; it is relevant also for the anti-proliferative activity of the retinoid in HCC1599 breast cancer cells, which are addicted to NOTCH1 for growth/viability. This effect is enhanced by the combination of ATRA and the γ-secretase inhibitor N-(N-(3,5-difluorophenacetyl)-l-alanyl)-S-phenylglycine t-butyl ester, supporting the concept that the two compounds act at the transcriptional and post-translational levels along the NOTCH1 pathway. PMID:26018078

  18. Designed modulation of sex steroid signaling inhibits telomerase activity and proliferation of human prostate cancer cells

    SciTech Connect

    Verma, Vikas; Sharma, Vikas; Singh, Vishal; Sharma, Siddharth; Bishnoi, Ajay Kumar; Chandra, Vishal; Maikhuri, J.P.; Dwivedi, Anila; Kumar, Atul; Gupta, Gopal

    2014-10-15

    The predominant estrogen-receptor (ER)-β signaling in normal prostate is countered by increased ER-α signaling in prostate cancer (CaP), which in association with androgen-receptor (AR) signaling results in pathogenesis of the disease. However CaP treatments mostly target AR signaling which is initially effective but eventually leads to androgen resistance, hence simultaneous targeting of ERs has been proposed. A novel series of molecules were designed with multiple sex-steroid receptor modulating capabilities by coalescing the pharmacophores of known anti-CaP molecules that act via modulation of ER(α/β) and/or AR, viz. 3,3′diindolylmethane (DIM), mifepristone, toremifene, tamoxifen and raloxifene. N,N-diethyl-4-((2-(4-methoxyphenyl)-1H-indol-3-yl)methyl) aniline (DIMA) was identified as the most promising structure of this new series. DIMA increased annexin-V labelling, cell-cycle arrest and caspase-3 activity, and decreased expression of AR and prostate specific antigen in LNCaP cells, in vitro. Concurrently, DIMA increased ER-β, p21 and p27 protein levels in LNCaP cells and exhibited ∼ 5 times more selective binding for ER-β than ER-α, in comparison to raloxifene. DIMA exhibited a dose-dependent ER-β agonism and ER-α antagonism in classical gene reporter assay and decreased hTERT (catalytic subunit of telomerase) transcript levels in LNCaP at 3.0 μM (P < 0.05). DIMA also dose-dependently decreased telomerase enzyme activity in prostate cancer cells. It is thus concluded that DIMA acts as a multi-steroid receptor modulator and effectively inhibits proliferation of prostate cancer cells through ER-β mediated telomerase inhibition, by countering actions of ER-α and AR. Its unique molecular design can serve as a lead structure for generation of potent agents against endocrine malignancies like the CaP.

  19. The general anaesthetic etomidate inhibits the excitability of mouse thalamocortical relay neurons by modulating multiple modes of GABAA receptor-mediated inhibition

    PubMed Central

    Herd, Murray B; Lambert, Jeremy J; Belelli, Delia

    2014-01-01

    Modulation of thalamocortical (TC) relay neuron function has been implicated in the sedative and hypnotic effects of general anaesthetics. Inhibition of TC neurons is mediated predominantly by a combination of phasic and tonic inhibition, together with a recently described ‘spillover’ mode of inhibition, generated by the dynamic recruitment of extrasynaptic γ-aminobutyric acid (GABA)A receptors (GABAARs). Previous studies demonstrated that the intravenous anaesthetic etomidate enhances tonic and phasic inhibition in TC relay neurons, but it is not known how etomidate may influence spillover inhibition. Moreover, it is unclear how etomidate influences the excitability of TC neurons. Thus, to investigate the relative contribution of synaptic (α1β2γ2) and extrasynaptic (α4β2δ) GABAARs to the thalamic effects of etomidate, we performed whole-cell recordings from mouse TC neurons lacking synaptic (α10/0) or extrasynaptic (δ0/0) GABAARs. Etomidate (3 μm) significantly inhibited action-potential discharge in a manner that was dependent on facilitation of both synaptic and extrasynaptic GABAARs, although enhanced tonic inhibition was dominant in this respect. Additionally, phasic inhibition evoked by stimulation of the nucleus reticularis exhibited a spillover component mediated by δ-GABAARs, which was significantly prolonged in the presence of etomidate. Thus, etomidate greatly enhanced the transient suppression of TC spike trains by evoked inhibitory postsynaptic potentials. Collectively, these results suggest that the deactivation of thalamus observed during etomidate-induced anaesthesia involves potentiation of tonic and phasic inhibition, and implicate amplification of spillover inhibition as a novel mechanism to regulate the gating of sensory information through the thalamus during anaesthetic states. PMID:24773078

  20. Copper Inhibits NMDA Receptor-Independent LTP and Modulates the Paired-Pulse Ratio after LTP in Mouse Hippocampal Slices.

    PubMed

    Salazar-Weber, Nina L; Smith, Jeffrey P

    2011-01-01

    Copper misregulation has been implicated in the pathological processes underlying deterioration of learning and memory in Alzheimer's disease and other neurodegenerative disorders. Supporting this, inhibition of long-term potentiation (LTP) by copper (II) has been well established, but the exact mechanism is poorly characterized. It is thought that an interaction between copper and postsynaptic NMDA receptors is a major part of the mechanism; however, in this study, we found that copper (II) inhibited NMDA receptor-independent LTP in the CA3 region of hippocampal slices. In addition, in the CA3 and CA1 regions, copper modulated the paired-pulse ratio (PPR) in an LTP-dependent manner. Combined, this suggests the involvement of a presynaptic mechanism in the modulation of synaptic plasticity by copper. Inhibition of the copper-dependent changes in the PPR with cyclothiazide suggested that this may involve an interaction with the presynaptic AMPA receptors that regulate neurotransmitter release.

  1. Müllerian inhibiting substance production and cleavage is modulated by gonadotropins and steroids.

    PubMed

    Kuroda, T; Lee, M M; Ragin, R C; Hirobe, S; Donahoe, P K

    1991-12-01

    Analysis of the ontogeny and localization of the amino (N)-terminal and carboxy (C)-terminal cleavage products of Müllerian Inhibiting Substance (MIS) and their modulation by hormones of the hypothalamic-pituitary gonadal axis by immunohistochemistry and Northern analysis led to the discovery of a novel mode of posttranslational regulation of this differentiating agent. Antibody to both holo- and C-terminal MIS identically stained the cytosol of testicular Sertoli cells from 21-day fetal rats, whereas staining of antibody to N-terminal MIS localized to the basement membrane of seminiferous tubules. In addition, when studied longitudinally, basement membrane staining for N-terminal MIS persisted; cytosolic staining for C-terminal MIS was no longer detectable in post-natal testes, but marked basement membrane staining for the N-terminal fragment could still be observed in the testes of untreated 7-day postnatal animals. When 19-day fetuses were injected with FSH, testes collected 2 days later showed less immunohistochemical staining for holo-, N-, and C-terminal MIS, and less MIS messenger RNA. This suggested that FSH downregulates MIS transcription, as had been shown previously in neonatal testes treated with FSH. Testes collected at 21 days from fetuses treated at day 19 in utero with human CG or testosterone, also showed less staining for holo-MIS, but, surprisingly, increased staining for the N- and C-terminal fragments. These changes in MIS protein were accompanied by no or minimal changes in MIS messenger RNA levels, indicating that human CG and testosterone do not affect transcription, but may regulate the cleavage and/or dissociation of MIS. This study describes a form of post-translational regulation of MIS and shows that both transcription and processing of MIS may be differentially modulated by gonadotropins and sex steroids.

  2. Pain facilitation and pain inhibition during conditioned pain modulation in fibromyalgia and in healthy controls.

    PubMed

    Potvin, Stéphane; Marchand, Serge

    2016-08-01

    Although fibromyalgia (FM) is associated with a deficit in inhibitory conditioned pain modulation (CPM), the discriminative power of CPM procedures is unknown. Moreover, the high intersubject heterogeneity in CPM responses in FM raises the possibility that a sizeable subgroup of these patients may experience pain facilitation during CPM, but the phenomenon has not been explicitly studied. To address these issues, 96 patients with FM and 71 healthy controls were recruited. Thermal stimuli were used to measure pain thresholds. Pain inhibition was elicited using a tonic thermal test (Peltier thermode) administered before and after activation of CPM mechanisms using a cold pressor test. Thermal pain thresholds were lower in patients with FM than in healthy controls. Pain ratings during the cold pressor test were higher in patients with FM, relative to controls. The CPM inhibitory efficacy was lower in patients with FM than in controls. The CPM procedure had good specificity (78.9%) but low sensitivity (45.7%), whereas a composite pain index had good sensitivity (75.0%) and specificity (78.9%). Finally, the rate of patients with FM who reported pain facilitation during the CPM procedure was found to be significantly increased compared with that of controls (41.7% vs 21.2%). The good discriminative power of the composite pain index highlights the need for further validation studies using mechanistically relevant psychophysical procedures in FM. The low sensitivity of the CPM procedure, combined with the large proportion of patients with FM experiencing pain facilitation during CPM, strongly suggests that endogenous pain inhibition mechanisms are deeply impaired in patients with FM, but only in a subgroup of them. PMID:27045524

  3. Pain facilitation and pain inhibition during conditioned pain modulation in fibromyalgia and in healthy controls.

    PubMed

    Potvin, Stéphane; Marchand, Serge

    2016-08-01

    Although fibromyalgia (FM) is associated with a deficit in inhibitory conditioned pain modulation (CPM), the discriminative power of CPM procedures is unknown. Moreover, the high intersubject heterogeneity in CPM responses in FM raises the possibility that a sizeable subgroup of these patients may experience pain facilitation during CPM, but the phenomenon has not been explicitly studied. To address these issues, 96 patients with FM and 71 healthy controls were recruited. Thermal stimuli were used to measure pain thresholds. Pain inhibition was elicited using a tonic thermal test (Peltier thermode) administered before and after activation of CPM mechanisms using a cold pressor test. Thermal pain thresholds were lower in patients with FM than in healthy controls. Pain ratings during the cold pressor test were higher in patients with FM, relative to controls. The CPM inhibitory efficacy was lower in patients with FM than in controls. The CPM procedure had good specificity (78.9%) but low sensitivity (45.7%), whereas a composite pain index had good sensitivity (75.0%) and specificity (78.9%). Finally, the rate of patients with FM who reported pain facilitation during the CPM procedure was found to be significantly increased compared with that of controls (41.7% vs 21.2%). The good discriminative power of the composite pain index highlights the need for further validation studies using mechanistically relevant psychophysical procedures in FM. The low sensitivity of the CPM procedure, combined with the large proportion of patients with FM experiencing pain facilitation during CPM, strongly suggests that endogenous pain inhibition mechanisms are deeply impaired in patients with FM, but only in a subgroup of them.

  4. Modulators of estrogen receptor inhibit proliferation and migration of prostate cancer cells.

    PubMed

    Piccolella, Margherita; Crippa, Valeria; Messi, Elio; Tetel, Marc J; Poletti, Angelo

    2014-01-01

    In the initial stages, human prostate cancer (PC) is an androgen-sensitive disease, which can be pharmacologically controlled by androgen blockade. This therapy often induces selection of androgen-independent PC cells with increased invasiveness. We recently demonstrated, both in cells and mice, that a testosterone metabolite locally synthetized in prostate, the 5α-androstane-3β, 17β-diol (3β-Adiol), inhibits PC cell proliferation, migration and invasion, acting as an anti-proliferative/anti-metastatic agent. 3β-Adiol is unable to bind androgen receptor (AR), but exerts its protection against PC by specifically interacting with estrogen receptor beta (ERβ). Because of its potential retro-conversion to androgenic steroids, 3β-Adiol cannot be used "in vivo", thus, the aims of this study were to investigate the capability of four ligands of ERβ (raloxifen, tamoxifen, genistein and curcumin) to counteract PC progression by mimicking the 3β-Adiol activity. Our results demonstrated that raloxifen, tamoxifen, genistein and curcumin decreased DU145 and PC3 cell proliferation in a dose-dependent manner; in addition, all four compounds significantly decreased the detachment of cells seeded on laminin or fibronectin. Moreover, raloxifen, tamoxifen, genistein and curcumin-treated DU145 and PC3 cells showed a significant decrease in cell migration. Notably, all these effects were reversed by the anti-estrogen, ICI 182,780, suggesting that their actions are mediated by the estrogenic pathway, via the ERβ, the only isoform present in these PCs. In conclusion, these data demonstrate that by selectively activating the ERβ, raloxifen, tamoxifen, genistein and curcumin inhibit human PC cells proliferation and migration favoring cell adesion. These synthetic and natural modulators of ER action may exert a potent protective activity against the progression of PC even in its androgen-independent status. PMID:24184124

  5. Response control networks are selectively modulated by attention to rare events and memory load regardless of the need for inhibition.

    PubMed

    Wijeakumar, Sobanawartiny; Magnotta, Vincent A; Buss, Aaron T; Ambrose, Joseph P; Wifall, Timothy A; Hazeltine, Eliot; Spencer, John P

    2015-10-15

    Recent evidence has sparked debate about the neural bases of response selection and inhibition. In the current study, we employed two reactive inhibition tasks, the Go/Nogo (GnG) and Simon tasks, to examine questions central to these debates. First, we investigated whether a fronto-cortical-striatal system was sensitive to the need for inhibition per se or the presentation of infrequent stimuli, by manipulating the proportion of trials that do not require inhibition (Go/Compatible trials) relative to trials that require inhibition (Nogo/Incompatible trials). A cortico-subcortical network composed of insula, putamen, and thalamus showed greater activation on salient and infrequent events, regardless of the need for inhibition. Thus, consistent with recent findings, key parts of the fronto-cortical-striatal system are engaged by salient events and do not appear to play a selective role in response inhibition. Second, we examined how the fronto-cortical-striatal system is modulated by working memory demands by varying the number of stimulus-response (SR) mappings. Right inferior parietal lobule showed decreasing activation as the number of SR mappings increased, suggesting that a form of associative memory - rather than working memory - might underlie performance in these tasks. A broad motor planning and control network showed similar trends that were also modulated by the number of motor responses required in each task. Finally, bilateral lingual gyri were more robustly engaged in the Simon task, consistent with the role of this area in shifts of visuo-spatial attention. The current study sheds light on how the fronto-cortical-striatal network is selectively engaged in reactive control tasks and how control is modulated by manipulations of attention and memory load. PMID:26190403

  6. Response control networks are selectively modulated by attention to rare events and memory load regardless of the need for inhibition.

    PubMed

    Wijeakumar, Sobanawartiny; Magnotta, Vincent A; Buss, Aaron T; Ambrose, Joseph P; Wifall, Timothy A; Hazeltine, Eliot; Spencer, John P

    2015-10-15

    Recent evidence has sparked debate about the neural bases of response selection and inhibition. In the current study, we employed two reactive inhibition tasks, the Go/Nogo (GnG) and Simon tasks, to examine questions central to these debates. First, we investigated whether a fronto-cortical-striatal system was sensitive to the need for inhibition per se or the presentation of infrequent stimuli, by manipulating the proportion of trials that do not require inhibition (Go/Compatible trials) relative to trials that require inhibition (Nogo/Incompatible trials). A cortico-subcortical network composed of insula, putamen, and thalamus showed greater activation on salient and infrequent events, regardless of the need for inhibition. Thus, consistent with recent findings, key parts of the fronto-cortical-striatal system are engaged by salient events and do not appear to play a selective role in response inhibition. Second, we examined how the fronto-cortical-striatal system is modulated by working memory demands by varying the number of stimulus-response (SR) mappings. Right inferior parietal lobule showed decreasing activation as the number of SR mappings increased, suggesting that a form of associative memory - rather than working memory - might underlie performance in these tasks. A broad motor planning and control network showed similar trends that were also modulated by the number of motor responses required in each task. Finally, bilateral lingual gyri were more robustly engaged in the Simon task, consistent with the role of this area in shifts of visuo-spatial attention. The current study sheds light on how the fronto-cortical-striatal network is selectively engaged in reactive control tasks and how control is modulated by manipulations of attention and memory load.

  7. Mitochondrial and Chloroplast Stress Responses Are Modulated in Distinct Touch and Chemical Inhibition Phases1[OPEN

    PubMed Central

    Ivanova, Aneta; Millar, A. Harvey; Whelan, James

    2016-01-01

    Previous studies have identified a range of transcription factors that modulate retrograde regulation of mitochondrial and chloroplast functions in Arabidopsis (Arabidopsis thaliana). However, the relative importance of these regulators and whether they act downstream of separate or overlapping signaling cascades is still unclear. Here, we demonstrate that multiple stress-related signaling pathways, with distinct kinetic signatures, converge on overlapping gene sets involved in energy organelle function. The transcription factor ANAC017 is almost solely responsible for transcript induction of marker genes around 3 to 6 h after chemical inhibition of organelle function and is a key regulator of mitochondrial and specific types of chloroplast retrograde signaling. However, an independent and highly transient gene expression phase, initiated within 10 to 30 min after treatment, also targets energy organelle functions, and is related to touch and wounding responses. Metabolite analysis demonstrates that this early response is concurrent with rapid changes in tricarboxylic acid cycle intermediates and large changes in transcript abundance of genes encoding mitochondrial dicarboxylate carrier proteins. It was further demonstrated that transcription factors AtWRKY15 and AtWRKY40 have repressive regulatory roles in this touch-responsive gene expression. Together, our results show that several regulatory systems can independently affect energy organelle function in response to stress, providing different means to exert operational control. PMID:27208304

  8. FDA-approved selective estrogen receptor modulators inhibit Ebola virus infection.

    PubMed

    Johansen, Lisa M; Brannan, Jennifer M; Delos, Sue E; Shoemaker, Charles J; Stossel, Andrea; Lear, Calli; Hoffstrom, Benjamin G; Dewald, Lisa Evans; Schornberg, Kathryn L; Scully, Corinne; Lehár, Joseph; Hensley, Lisa E; White, Judith M; Olinger, Gene G

    2013-06-19

    Ebola viruses remain a substantial threat to both civilian and military populations as bioweapons, during sporadic outbreaks, and from the possibility of accidental importation from endemic regions by infected individuals. Currently, no approved therapeutics exist to treat or prevent infection by Ebola viruses. Therefore, we performed an in vitro screen of Food and Drug Administration (FDA)- and ex-US-approved drugs and selected molecular probes to identify drugs with antiviral activity against the type species Zaire ebolavirus (EBOV). From this screen, we identified a set of selective estrogen receptor modulators (SERMs), including clomiphene and toremifene, which act as potent inhibitors of EBOV infection. Anti-EBOV activity was confirmed for both of these SERMs in an in vivo mouse infection model. This anti-EBOV activity occurred even in the absence of detectable estrogen receptor expression, and both SERMs inhibited virus entry after internalization, suggesting that clomiphene and toremifene are not working through classical pathways associated with the estrogen receptor. Instead, the response appeared to be an off-target effect where the compounds interfere with a step late in viral entry and likely affect the triggering of fusion. These data support the screening of readily available approved drugs to identify therapeutics for the Ebola viruses and other infectious diseases. The SERM compounds described in this report are an immediately actionable class of approved drugs that can be repurposed for treatment of filovirus infections.

  9. A Legionella effector modulates host cytoskeletal structure by inhibiting actin polymerization

    PubMed Central

    Guo, Zhenhua; Stephenson, Robert; Qiu, Jiazhang; Zheng, Shijun; Luo, Zhao-Qing

    2014-01-01

    Successful infection by the opportunistic pathogen Legionella pneumophila requires the collective activity of hundreds of virulence proteins delivered into the host cell by the Dot/Icm type IV secretion system. These virulence proteins, also called effectors modulate distinct host cellular processes to create a membrane-bound niche called the Legionella containing vacuole (LCV) supportive of bacterial growth. We found that Ceg14(Lpg0437), a Dot/Icm substrate is toxic to yeast and such toxicity can be alleviated by overexpression of profilin, a protein involved in cytoskeletal structure in eukaryotes. We further showed that mutations in profilin affect actin binding but not other functions such as interactions with poly-L-proline or phosphatidylinositol, abolish its suppressor activity. Consistent with the fact the profilin suppresses its toxicity, expression of Ceg14 but not its non-toxic mutants in yeast affects actin distribution and budding of daughter cells. Although Ceg14 does not detectably interact with profilin, it co-sediments with filamentous actin and inhibits actin polymerization, causing the accumulation of short actin filaments. These results reveal that multiple L. pneumophila effectors target components of the host cytoskeleton. PMID:24286927

  10. Fibroblastic Transformation of Corneal Keratocytes by Rac Inhibition is Modulated by Extracellular Matrix Structure and Stiffness

    PubMed Central

    Petroll, W. Matthew; Lakshman, Neema

    2015-01-01

    The goal of this study was to investigate how alterations in extracellular matrix (ECM) biophysical properties modulate corneal keratocyte phenotypes in response to specific wound healing cytokines and Rho GTPases. Rabbit corneal keratocytes were plated within standard collagen matrices (2.5 mg/mL) or compressed collagen matrices (~100 mg/mL) and cultured in serum-free media, PDGF BB, IGF, FGF2 or TGFβ1, with or without the Rac1 inhibitor NSC23766 and/or the Rho kinase inhibitor Y-27632. After 1 to 4 days, cells were labeled for F-actin and imaged using confocal microscopy. Keratocytes within standard collagen matrices (which are highly compliant) maintained a dendritic phenotype following culture in serum-free media, PDGF, IGF and FGF, but developed stress fibers in TGFβ1. Keratocytes within compressed collagen (which has high stiffness and low porosity) maintained a dendritic phenotype following culture in serum-free media, PDGF and IGF, but developed stress fibers in both FGF and TGFβ1. The Rac inhibitor had no significant impact on growth factor responses in compliant matrices. Within compressed collagen matrices however, the Rac inhibitor induced fibroblastic transformation in serum-free media, PDGF and IGF. Fibroblast and myofibroblast transformation was blocked by Rho kinase inhibition. Overall, keratocyte growth factor responses appear to be regulated by both the interplay between Rho and Rac signaling, and the structural and mechanical properties of the ECM. PMID:25874856

  11. Fibroblastic Transformation of Corneal Keratocytes by Rac Inhibition is Modulated by Extracellular Matrix Structure and Stiffness.

    PubMed

    Petroll, W Matthew; Lakshman, Neema

    2015-04-14

    The goal of this study was to investigate how alterations in extracellular matrix (ECM) biophysical properties modulate corneal keratocyte phenotypes in response to specific wound healing cytokines and Rho GTPases. Rabbit corneal keratocytes were plated within standard collagen matrices (2.5 mg/mL) or compressed collagen matrices (~100 mg/mL) and cultured in serum-free media, PDGF BB, IGF, FGF2 or TGFβ1, with or without the Rac1 inhibitor NSC23766 and/or the Rho kinase inhibitor Y-27632. After 1 to 4 days, cells were labeled for F-actin and imaged using confocal microscopy. Keratocytes within standard collagen matrices (which are highly compliant) maintained a dendritic phenotype following culture in serum-free media, PDGF, IGF and FGF, but developed stress fibers in TGFβ1. Keratocytes within compressed collagen (which has high stiffness and low porosity) maintained a dendritic phenotype following culture in serum-free media, PDGF and IGF, but developed stress fibers in both FGF and TGFβ1. The Rac inhibitor had no significant impact on growth factor responses in compliant matrices. Within compressed collagen matrices however, the Rac inhibitor induced fibroblastic transformation in serum-free media, PDGF and IGF. Fibroblast and myofibroblast transformation was blocked by Rho kinase inhibition. Overall, keratocyte growth factor responses appear to be regulated by both the interplay between Rho and Rac signaling, and the structural and mechanical properties of the ECM.

  12. Rootin, a compound that inhibits root development through modulating PIN-mediated auxin distribution.

    PubMed

    Jeong, Suyeong; Kim, Jun-Young; Choi, Hyunmo; Kim, Hyunmin; Lee, Ilhwan; Soh, Moon-Soo; Nam, Hong Gil; Chang, Young-Tae; Lim, Pyung Ok; Woo, Hye Ryun

    2015-04-01

    Plant roots anchor the plant to the soil and absorb water and nutrients for growth. Understanding the molecular mechanisms regulating root development is essential for improving plant survival and agricultural productivity. Extensive molecular genetic studies have provided important information on crucial components for the root development control over the last few decades. However, it is becoming difficult to identify new regulatory components in root development due to the functional redundancy and lethality of genes involved in root development. In this study, we performed a chemical genetic screen to identify novel synthetic compounds that regulate root development in Arabidopsis seedlings. The screen yielded a root growth inhibitor designated as 'rootin', which inhibited Arabidopsis root development by modulating cell division and elongation, but did not significantly affect shoot development. Transcript analysis of phytohormone marker genes revealed that rootin preferentially altered the expression of auxin-regulated genes. Furthermore, rootin reduced the accumulation of PIN1, PIN3, and PIN7 proteins, and affected the auxin distribution in roots, which consequently may lead to the observed defects in root development. Our results suggest that rootin could be utilized to unravel the mechanisms underlying root development and to investigate dynamic changes in PIN-mediated auxin distribution. PMID:25711819

  13. Interferon-gamma inhibits central nervous system remyelination through a process modulated by endoplasmic reticulum stress.

    PubMed

    Lin, Wensheng; Kemper, April; Dupree, Jeffrey L; Harding, Heather P; Ron, David; Popko, Brian

    2006-05-01

    Interferon-gamma (IFN-gamma) is believed to play a deleterious role in the immune-mediated demyelinating disorder multiple sclerosis. Here we have exploited transgenic mice that ectopically express IFN-gamma in a temporally controlled manner in the CNS to specifically study its effects on remyelination in the cuprizone-induced demyelination model and in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. CNS delivery of IFN-gamma severely suppressed remyelination in both models and impaired the clinical recovery of the mice experiencing EAE. These observations correlated with a dramatic reduction of oligodendroglial repopulation in the demyelinated lesions. Moreover, we found that in cuprizone-treated mice the detrimental actions of IFN-gamma were associated with endoplasmic reticulum (ER) stress in remyelinating oligodendrocytes. Compared with a wild-type genetic background, the presence of IFN-gamma in mice heterozygous for a loss of function mutation in the pancreatic ER kinase (PERK), a kinase that responds specifically to ER stress, further reduced the percentage of remyelinated axons and oligodendrocyte numbers in cuprizone-induced demyelinated lesions. Thus, these data suggest that IFN-gamma is capable of inhibiting remyelination in demyelinated lesions and that ER stress modulates the response of remyelinating oligodendrocytes to this cytokine. PMID:16504972

  14. Dopamine D₂ receptor modulation of human response inhibition and error awareness.

    PubMed

    Nandam, L Sanjay; Hester, Robert; Wagner, Joe; Dean, Angela J; Messer, Cassandra; Honeysett, Asha; Nathan, Pradeep J; Bellgrove, Mark A

    2013-04-01

    Response inhibition, comprising action cancellation and action restraint, and error awareness are executive functions of considerable clinical relevance to neuropsychiatric disorders. Nevertheless, our understanding of their underlying catecholamine mechanisms, particularly regarding dopamine, is limited. Here, we used the dopamine D2 agonist cabergoline to study its ability to improve inhibitory control and modulate awareness of performance errors. A randomized, double-blind, placebo-controlled, crossover design with a single dose of cabergoline (1.25 mg) and placebo (dextrose) was employed in 25 healthy participants. They each performed the stop-signal task, a well-validated measure of action cancellation, and the Error Awareness Task, a go/no-go measure of action restraint and error awareness, under each drug condition. Cabergoline was able to selectively reduce stop-signal RT, compared with placebo, indicative of enhanced action cancellation (p < .05). This enhancement occurred without concomitant changes in overall response speed or RT variability and was not seen for errors of commission on the Error Awareness Task. Awareness of performance errors on the go/no-go task was, however, significantly improved by cabergoline compared with placebo (p < .05). Our results contribute to growing evidence for the dopaminergic control of distinct aspects of human executive ability, namely, action cancellation and error awareness. The findings may aid the development of new, or the repurposing of existing, pharmacotherapy that targets the cognitive dysfunction of psychiatric and neurological disorders. They also provide further evidence that specific cognitive paradigms have correspondingly specific neurochemical bases. PMID:23163418

  15. Pentosan polysulfate inhibits atherosclerosis in Watanabe heritable hyperlipidemic rabbits: differential modulation of metalloproteinase-2 and -9.

    PubMed

    Lupia, Enrico; Zheng, Feng; Grosjean, Fabrizio; Tack, Ivan; Doublier, Sophie; Elliot, Sharon J; Vlassara, Helen; Striker, Gary E

    2012-02-01

    Pentosan polysulfate (PPS), a heparinoid compound essentially devoid of anticoagulant activity, modulates cell growth and decreases inflammation. We investigated the effect of PPS on the progression of established atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits. After severe atherosclerosis developed on an atherogenic diet, WHHL rabbits were treated with oral PPS or tap water for 1 month. The aortic intima-to-media ratio and macrophage infiltration were reduced, plaque collagen content was increased, and plaque fibrous caps were preserved by PPS treatment. Plasma lipid levels and post-heparin hepatic lipase activity remained unchanged. However, net collagenolytic activity in aortic extracts was decreased, and the levels of matrix metalloproteinase (MMP)-2 and tissue inhibitor of metalloproteinase (TIMP) activity were increased by PPS. Moreover, PPS treatment decreased tumor necrosis factor α (TNFα)-stimulated proinflammatory responses, in particular activation of nuclear factor-κB and p38, and activation of MMPs in macrophages. In conclusion, oral PPS treatment prevents progression of established atherosclerosis in WHHL rabbits. This effect may be partially mediated by increased MMP-2 and TIMP activities in the aortic wall and reduced TNFα-stimulated inflammation and MMP activation in macrophages. Thus, PPS may be a useful agent in inhibiting the progression of atherosclerosis.

  16. Context-dependent modulation of alphabetagamma and alphabetadelta GABA A receptors by penicillin: implications for phasic and tonic inhibition.

    PubMed

    Feng, Hua-Jun; Botzolakis, Emmanuel J; Macdonald, Robert L

    2009-01-01

    Penicillin, an open-channel blocker of GABA(A) receptors, was recently reported to inhibit phasic, but not tonic, currents in hippocampal neurons. To distinguish between isoform-specific and context-dependent modulation as possible explanations for this selectivity, the effects of penicillin were evaluated on recombinant GABA(A) receptors expressed in HEK293T cells. When co-applied with saturating GABA, penicillin decreased peak amplitude, induced rebound, and prolonged deactivation of currents evoked from both synaptic and extrasynaptic receptor isoforms. However, penicillin had isoform-specific effects on the extent of desensitization, reflecting its ability to differentially modulate peak (non-equilibrium) and residual (near-equilibrium) currents. This suggested that the context of activation could determine the apparent sensitivity of a given receptor isoform to penicillin. To test this hypothesis, we explored the ability of penicillin to modulate synaptic and extrasynaptic isoform currents that were activated under more physiologically relevant conditions. Interestingly, while currents evoked from synaptic isoforms under phasic conditions (transient activation by a saturating concentration of GABA) were substantially inhibited by penicillin, currents evoked from extrasynaptic isoforms under tonic conditions (prolonged application by a sub-saturating concentration of GABA) were minimally affected. We therefore concluded that the reported inability of penicillin to modulate tonic currents could not simply be attributed to insensitivity of extrasynaptic receptors, but rather, reflected an inability to modulate these receptors in their native context of activation.

  17. Inhibition of angiogenesis by selective estrogen receptor modulators through blockade of cholesterol trafficking rather than estrogen receptor antagonism.

    PubMed

    Shim, Joong Sup; Li, Ruo-Jing; Lv, Junfang; Head, Sarah A; Yang, Eun Ju; Liu, Jun O

    2015-06-28

    Selective estrogen receptor modulators (SERM) including tamoxifen are known to inhibit angiogenesis. However, the underlying mechanism, which is independent of their action on the estrogen receptor (ER), has remained largely unknown. In the present study, we found that tamoxifen and other SERM inhibited cholesterol trafficking in endothelial cells, causing a hyper-accumulation of cholesterol in late endosomes/lysosomes. Inhibition of cholesterol trafficking by tamoxifen was accompanied by abnormal subcellular distribution of vascular endothelial growth factor receptor-2 (VEGFR2) and inhibition of the terminal glycosylation of the receptor. Tamoxifen also caused perinuclear positioning of lysosomes, which in turn trapped the mammalian target of rapamycin (mTOR) in the perinuclear region of endothelial cells. Abnormal distribution of VEGFR2 and mTOR and inhibition of VEGFR2 and mTOR activities by tamoxifen were significantly reversed by addition of cholesterol-cyclodextrin complex to the culture media of endothelial cells. Moreover, high concentrations of tamoxifen inhibited endothelial and breast cancer cell proliferation in a cholesterol-dependent, but ER-independent, manner. Together, these results unraveled a previously unrecognized mechanism of angiogenesis inhibition by tamoxifen and other SERM, implicating cholesterol trafficking as an attractive therapeutic target for cancer treatment.

  18. Modulation of phosphatidylcholine synthesis in vitro. Inhibition of diacylglycerol cholinephosphotransferase and lysophosphatidylcholine acyltransferase by centrophenoxine and neophenoxine.

    PubMed

    Parthasarathy, S; El-Rahman, A; Baumann, W J

    1981-08-24

    1,2-Diacyl-sn-glycerol : CDPcholine cholinephosphotransferase (EC 2.7.8.2) and acyl-CoA : 1-acyl-sn-glycero-3-phosphocholine acyltransferase (EC 2.3.1.23) activities of rat liver microsomes can be inhibited by centrophenoxine (N,N-dimethylaminoethyl p-chlorophenoxyacetate). This inhibition is brought about by the intact centrophenoxine molecule rather than by the products of hydrolysis. A nonhydrolyzable ether analog of centrophenoxine was synthesized (neophenoxine; N,N-dimethylaminoethyl p-chlorophenoxyethyl ether) and proved most effective in inhibiting the two routes of phosphatidylcholine biosynthesis. While 50% inhibition of the cholinephosphotransferase was attained at 5 mM neophenoxine, 50% inhibition of the acyltransferase required 0.6 mM neophenoxine levels only. Inhibition of the cholinephosphotransferase (Ki approximately 1.5 mM) and the acyltransferase (Ki approximately 1 mM) by neophenoxine was shown to be noncompetitive. Other membrane-bound enzymes, such as glucose-6-phosphatase, monoacylglycerol lipase, alkaline phosphatase or phospholipase A2 were not affected by the inhibitors. Because of this specificity, and because of the high affinity of the microsomal membrane for such agents, centrophenoxine and neophenoxine should prove useful for controlling phosphatidylcholine synthesis and for modulating the phosphatidylcholine deacylation-reacylation cycle.

  19. Tonic Inhibition of Accumbal Spiny Neurons by Extrasynaptic α4βδ GABAA Receptors Modulates the Actions of Psychostimulants

    PubMed Central

    Maguire, Edward P.; Macpherson, Tom; Swinny, Jerome D.; Dixon, Claire I.; Herd, Murray B.; Belelli, Delia; Stephens, David N.

    2014-01-01

    Within the nucleus accumbens (NAc), synaptic GABAA receptors (GABAARs) mediate phasic inhibition of medium spiny neurons (MSNs) and influence behavioral responses to cocaine. We demonstrate that both dopamine D1- and D2-receptor-expressing MSNs (D-MSNs) additionally harbor extrasynaptic GABAARs incorporating α4, β, and δ subunits that mediate tonic inhibition, thereby influencing neuronal excitability. Both the selective δ-GABAAR agonist THIP and DS2, a selective positive allosteric modulator, greatly increased the tonic current of all MSNs from wild-type (WT), but not from δ−/− or α4−/− mice. Coupling dopamine and tonic inhibition, the acute activation of D1 receptors (by a selective agonist or indirectly by amphetamine) greatly enhanced tonic inhibition in D1-MSNs but not D2-MSNs. In contrast, prolonged D2 receptor activation modestly reduced the tonic conductance of D2-MSNs. Behaviorally, WT and constitutive α4−/− mice did not differ in their expression of cocaine-conditioned place preference (CPP). Importantly, however, mice with the α4 deletion specific to D1-expressing neurons (α4D1−/−) showed increased CPP. Furthermore, THIP administered systemically or directly into the NAc of WT, but not α4−/− or α4D1−/− mice, blocked cocaine enhancement of CPP. In comparison, α4D2−/− mice exhibited normal CPP, but no cocaine enhancement. In conclusion, dopamine modulation of GABAergic tonic inhibition of D1- and D2-MSNs provides an intrinsic mechanism to differentially affect their excitability in response to psychostimulants and thereby influence their ability to potentiate conditioned reward. Therefore, α4βδ GABAARs may represent a viable target for the development of novel therapeutics to better understand and influence addictive behaviors. PMID:24431441

  20. Hispolon inhibits the growth of estrogen receptor positive human breast cancer cells through modulation of estrogen receptor alpha

    SciTech Connect

    Jang, Eun Hyang; Jang, Soon Young; Cho, In-Hye; Hong, Darong; Jung, Bom; Park, Min-Ju; Kim, Jong-Ho

    2015-08-07

    Human estrogen receptor α (ERα) is a nuclear transcription factor that is a major therapeutic target in breast cancer. The transcriptional activity of ERα is regulated by certain estrogen-receptor modulators. Hispolon, isolated from Phellinus linteus, a traditional medicinal mushroom called Sanghwang in Korea, has been used to treat various pathologies, such as inflammation, gastroenteric disorders, lymphatic diseases, and cancers. In this latter context, Hispolon has been reported to exhibit therapeutic efficacy against various cancer cells, including melanoma, leukemia, hepatocarcinoma, bladder cancer, and gastric cancer cells. However, ERα regulation by Hispolon has not been reported. In this study, we investigated the effects of Hispolon on the growth of breast cancer cells. We found that Hispolon decreased expression of ERα at both mRNA and the protein levels in MCF7 and T47D human breast cancer cells. Luciferase reporter assays showed that Hispolon decreased the transcriptional activity of ERα. Hispolon treatment also inhibited expression of the ERα target gene pS2. We propose that Hispolon, an anticancer drug extracted from natural sources, inhibits cell growth through modulation of ERα in estrogen-positive breast cancer cells and is a candidate for use in human breast cancer chemotherapy. - Highlights: • Hispolon decreased ERα expression at both mRNA and protein levels. • Hispolon decreased ERα transcriptional activity. • Hispolon treatment inhibited expression of ERα target gene pS2. • Shikonin is a candidate chemotherapeutic target in the treatment of human breast cancer.

  1. Modulation of dendritic cell immunobiology via inhibition of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase.

    PubMed

    Leuenberger, Tina; Pfueller, Caspar F; Luessi, Felix; Bendix, Ivo; Paterka, Magdalena; Prozorovski, Timour; Treue, Denise; Luenstedt, Sarah; Herz, Josephine; Siffrin, Volker; Infante-Duarte, Carmen; Zipp, Frauke; Waiczies, Sonia

    2014-01-01

    The maturation status of dendritic cells determines whether interacting T cells are activated or if they become tolerant. Previously we could induce T cell tolerance by applying a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor (HMGCRI) atorvastatin, which also modulates MHC class II expression and has therapeutic potential in autoimmune disease. Here, we aimed at elucidating the impact of this therapeutic strategy on T cell differentiation as a consequence of alterations in dendritic cell function. We investigated the effect of HMGCRI during differentiation of peripheral human monocytes and murine bone marrow precursors to immature DC in vitro and assessed their phenotype. To examine the stimulatory and tolerogenic capacity of these modulated immature dendritic cells, we measured proliferation and suppressive function of CD4+ T cells after stimulation with the modulated immature dendritic cells. We found that an HMGCRI, atorvastatin, prevents dendrite formation during the generation of immature dendritic cells. The modulated immature dendritic cells had a diminished capacity to take up and present antigen as well as to induce an immune response. Of note, the consequence was an increased capacity to differentiate naïve T cells towards a suppressor phenotype that is less sensitive to proinflammatory stimuli and can effectively inhibit the proliferation of T effector cells in vitro. Thus, manipulation of antigen-presenting cells by HMGCRI contributes to an attenuated immune response as shown by promotion of T cells with suppressive capacities.

  2. Electrochemical activation and inhibition of neuromuscular systems through modulation of ion concentrations with ion-selective membranes

    NASA Astrophysics Data System (ADS)

    Song, Yong-Ak; Melik, Rohat; Rabie, Amr N.; Ibrahim, Ahmed M. S.; Moses, David; Tan, Ara; Han, Jongyoon; Lin, Samuel J.

    2011-12-01

    Conventional functional electrical stimulation aims to restore functional motor activity of patients with disabilities resulting from spinal cord injury or neurological disorders. However, intervention with functional electrical stimulation in neurological diseases lacks an effective implantable method that suppresses unwanted nerve signals. We have developed an electrochemical method to activate and inhibit a nerve by electrically modulating ion concentrations in situ along the nerve. Using ion-selective membranes to achieve different excitability states of the nerve, we observe either a reduction of the electrical threshold for stimulation by up to approximately 40%, or voluntary, reversible inhibition of nerve signal propagation. This low-threshold electrochemical stimulation method is applicable in current implantable neuroprosthetic devices, whereas the on-demand nerve-blocking mechanism could offer effective clinical intervention in disease states caused by uncontrolled nerve activation, such as epilepsy and chronic pain syndromes.

  3. Heparin-disaccharide affects T cells: inhibition of NF-kappaB activation, cell migration, and modulation of intracellular signaling.

    PubMed

    Hecht, Iris; Hershkoviz, Rami; Shivtiel, Shoham; Lapidot, Tzvi; Cohen, Irun R; Lider, Ofer; Cahalon, Liora

    2004-06-01

    We previously reported that disaccharides (DS), generated by enzymatic degradation of heparin or heparan sulfate, inhibit T cell-mediated immune reactions in rodents and regulate cytokine [tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-8, and IL-1beta] secretion by T cells, macrophages, or intestinal epithelial cells. Here, we investigated the effects of a trisulfated heparin DS (3S-DS) on two aspects of T cell function: secretion of proinflammatory cytokines and migration to an inflamed site. 3S-DS down-regulated nuclear factor-kappaB activity and reduced the secretion of TNF-alpha and interferon-gamma (IFN-gamma) by anti-CD3-activated T cells. In addition, 3S-DS inhibited CXC chemokine ligand 12 (CXCL12; stromal cell-derived factor-1alpha)-dependent migration in vitro and in vivo and decreased CXCL12-induced T cell adhesion to the extracellular matrix glycoprotein, fibronectin (FN). This inhibition was accompanied by attenuation of CXCL12-induced Pyk2 phosphorylation but did not involve internalization of the CXCL12 receptor, CXCR4, or phosphorylation of extracellular-regulated kinase. Despite inhibiting CXCL12-induced adhesion, 3S-DS, on its own, induced T cell adhesion to FN, which was accompanied by phosphorylation of Pyk2. A monosulfated DS showed no effect. Taken together, these data provide evidence that 3S-DS can regulate inflammation by inducing and modulating T cell-signaling events, desensitizing CXCR4, and modulating T cell receptor-induced responses. PMID:15020655

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

    PubMed Central

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

    2016-01-01

    Metabolites of the kynurenine pathway (KP) of tryptophan (TRP) degradation have been closely linked to the pathogenesis of several neurodegenerative disorders. Recent work has highlighted the therapeutic potential of inhibiting two critical regulatory enzymes in this pathway—kynurenine-3-monooxygenase (KMO) and tryptophan-2,3-dioxygenase (TDO). Much evidence indicates that the efficacy of KMO inhibition arises from normalizing an imbalance between neurotoxic [3-hydroxykynurenine (3-HK); quinolinic acid (QUIN)] and neuroprotective [kynurenic acid (KYNA)] KP metabolites. However, it is not clear if TDO inhibition is protective via a similar mechanism or if this is instead due to increased levels of TRP—the substrate of TDO. Here, we find that increased levels of KYNA relative to 3-HK are likely central to the protection conferred by TDO inhibition in a fruit fly model of Huntington’s disease and that TRP treatment strongly reduces neurodegeneration by shifting KP flux toward KYNA synthesis. In fly models of Alzheimer’s and Parkinson’s disease, we provide genetic evidence that inhibition of TDO or KMO improves locomotor performance and ameliorates shortened life span, as well as reducing neurodegeneration in Alzheimer's model flies. Critically, we find that treatment with a chemical TDO inhibitor is robustly protective in these models. Consequently, our work strongly supports targeting of the KP as a potential treatment strategy for several major neurodegenerative disorders and suggests that alterations in the levels of neuroactive KP metabolites could underlie several therapeutic benefits. PMID:27114543

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

    PubMed

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

    2016-05-10

    Metabolites of the kynurenine pathway (KP) of tryptophan (TRP) degradation have been closely linked to the pathogenesis of several neurodegenerative disorders. Recent work has highlighted the therapeutic potential of inhibiting two critical regulatory enzymes in this pathway-kynurenine-3-monooxygenase (KMO) and tryptophan-2,3-dioxygenase (TDO). Much evidence indicates that the efficacy of KMO inhibition arises from normalizing an imbalance between neurotoxic [3-hydroxykynurenine (3-HK); quinolinic acid (QUIN)] and neuroprotective [kynurenic acid (KYNA)] KP metabolites. However, it is not clear if TDO inhibition is protective via a similar mechanism or if this is instead due to increased levels of TRP-the substrate of TDO. Here, we find that increased levels of KYNA relative to 3-HK are likely central to the protection conferred by TDO inhibition in a fruit fly model of Huntington's disease and that TRP treatment strongly reduces neurodegeneration by shifting KP flux toward KYNA synthesis. In fly models of Alzheimer's and Parkinson's disease, we provide genetic evidence that inhibition of TDO or KMO improves locomotor performance and ameliorates shortened life span, as well as reducing neurodegeneration in Alzheimer's model flies. Critically, we find that treatment with a chemical TDO inhibitor is robustly protective in these models. Consequently, our work strongly supports targeting of the KP as a potential treatment strategy for several major neurodegenerative disorders and suggests that alterations in the levels of neuroactive KP metabolites could underlie several therapeutic benefits. PMID:27114543

  6. Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees

    PubMed Central

    Hordacre, Brenton; Bradnam, Lynley V.; Barr, Christopher; Patritti, Benjamin L.; Crotty, Maria

    2015-01-01

    Reorganization of primary motor cortex (M1) is well-described in long-term lower limb amputees. In contrast cortical reorganization during the rehabilitation period after amputation is poorly understood. Thirteen transtibial amputees and 13 gender matched control participants of similar age were recruited. Transcranial magnetic stimulation was used to assess corticomotor and intracortical excitability of M1 bilaterally. Neurophysiological assessments were conducted at admission, prosthetic casting, first walk and discharge. Gait variability at discharge was assessed as a functional measure. Compared to controls, amputees had reduced short-latency intracortical inhibition (SICI) for the ipsilateral M1 at admission (p = 0.01). Analysis across rehabilitation revealed SICI was reduced for the contralateral M1 at first walk compared to discharge (p = 0.003). For the ipsilateral M1 both short and long-latency intracortical inhibition were reduced at admission (p < 0.05) and prosthetic casting (p < 0.02). Analysis of the neurophysiology and gait function revealed several interesting relationships. For the contralateral M1, reduced inhibition at admission (p = 0.04) and first walk (p = 0.05) was associated with better gait function. For the ipsilateral M1, reduced inhibition at discharge (p = 0.05) was associated with poor gait function. This study characterized intracortical excitability in rehabilitating amputees. A dichotomous relationship between reduced intracortical inhibition for each M1 and gait function was observed at different times. Intracortical inhibition may be an appropriate cortical biomarker of gait function in lower limb amputees during rehabilitation, but requires further investigation. Understanding M1 intracortical excitability of amputees undertaking prosthetic rehabilitation provides insight into brain reorganization in the sub-acute post-amputation period and may guide future studies seeking to improve rehabilitation outcomes. PMID:26042015

  7. Enriched inhibition of cancer and stem-like cancer cells via STAT-3 modulating niclocelles

    NASA Astrophysics Data System (ADS)

    Misra, Santosh K.; Jensen, Tor W.; Pan, Dipanjan

    2015-04-01

    We describe for the first time a therapeutic strategy to target stem-like cancer cells via STAT-3 modulation using a nanomedicine approach. Niclocelle, a niclosamide loaded rigid core mixed micelle, was synthesized from a self-assembled well-defined amphiphilic diblock copolymer and an FDA-approved signal transducer and activator of transcription factor 3. Followed by a rigorous physico-chemical characterization, niclocelles were evaluated biologically for cytotoxicity and apoptosis in human melanoma (C32) and breast cancer (MDA-MB231 and MCF-7) cells. Niclocelles were found to selectively reduce the CD44+ stem cell population in C32 cells via STAT-3 modulation.We describe for the first time a therapeutic strategy to target stem-like cancer cells via STAT-3 modulation using a nanomedicine approach. Niclocelle, a niclosamide loaded rigid core mixed micelle, was synthesized from a self-assembled well-defined amphiphilic diblock copolymer and an FDA-approved signal transducer and activator of transcription factor 3. Followed by a rigorous physico-chemical characterization, niclocelles were evaluated biologically for cytotoxicity and apoptosis in human melanoma (C32) and breast cancer (MDA-MB231 and MCF-7) cells. Niclocelles were found to selectively reduce the CD44+ stem cell population in C32 cells via STAT-3 modulation. Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c5nr00403a

  8. Inhibition of RNA interference and modulation of transposable element expression by cell death in Drosophila.

    PubMed

    Xie, Weiwu; Liang, Chengzhi; Birchler, James A

    2011-08-01

    RNA interference (RNAi) regulates gene expression by sequence-specific destruction of RNA. It acts as a defense mechanism against viruses and represses the expression of transposable elements (TEs) and some endogenous genes. We report that mutations and transgene constructs that condition cell death suppress RNA interference in adjacent cells in Drosophila melanogaster. The reversal of RNAi is effective for both the white (w) eye color gene and green fluorescent protein (GFP), indicating the generality of the inhibition. Antiapoptotic transgenes that reverse cell death will also reverse the inhibition of RNAi. Using GFP and a low level of cell death produced by a heat shock-head involution defective (hs-hid) transgene, the inhibition appears to occur by blocking the conversion of double-stranded RNA (dsRNA) to short interfering RNA (siRNA). We also demonstrate that the mus308 gene and endogenous transposable elements, which are both regularly silenced by RNAi, are increased in expression and accompanied by a reduced level of siRNA, when cell death occurs. The finding that chronic ectopic cell death affects RNAi is critical for an understanding of the application of the technique in basic and applied studies. These results also suggest that developmental perturbations, disease states, or environmental insults that cause ectopic cell death would alter transposon and gene expression patterns in the organism by the inhibition of small RNA silencing processes. PMID:21596898

  9. Fourth-Generation Progestins Inhibit 3β-Hydroxysteroid Dehydrogenase Type 2 and Modulate the Biosynthesis of Endogenous Steroids

    PubMed Central

    Louw-du Toit, Renate; Perkins, Meghan S.; Snoep, Jacky L.; Storbeck, Karl-Heinz; Africander, Donita

    2016-01-01

    Progestins used in contraception and hormone replacement therapy are synthetic compounds designed to mimic the actions of the natural hormone progesterone and are classed into four consecutive generations. The biological actions of progestins are primarily determined by their interactions with steroid receptors, and factors such as metabolism, pharmacokinetics, bioavailability and the regulation of endogenous steroid hormone biosynthesis are often overlooked. Although some studies have investigated the effects of select progestins on a few steroidogenic enzymes, studies comparing the effects of progestins from different generations are lacking. This study therefore explored the putative modulatory effects of progestins on de novo steroid synthesis in the adrenal by comparing the effects of select progestins from the respective generations, on endogenous steroid hormone production by the H295R human adrenocortical carcinoma cell line. Ultra-performance liquid chromatography/tandem mass spectrometry analysis showed that the fourth-generation progestins, nestorone (NES), nomegestrol acetate (NoMAC) and drospirenone (DRSP), unlike the progestins selected from the first three generations, modulate the biosynthesis of several endogenous steroids. Subsequent assays performed in COS-1 cells expressing human 3βHSD2, suggest that these progestins modulate the biosynthesis of steroid hormones by inhibiting the activity of 3βHSD2. The Ki values determined for the inhibition of human 3βHSD2 by NES (9.5 ± 0.96 nM), NoMAC (29 ± 7.1 nM) and DRSP (232 ± 38 nM) were within the reported concentration ranges for the contraceptive use of these progestins in vivo. Taken together, our results suggest that newer, fourth-generation progestins may exert both positive and negative physiological effects via the modulation of endogenous steroid hormone biosynthesis. PMID:27706226

  10. Macrophages and lymphocytes differentially modulate the ability of RANTES to inhibit HIV-1 infection.

    PubMed

    Gross, Eleanore; Amella, Carol A; Pompucci, Lorena; Franchin, Giovanni; Sherry, Barbara; Schmidtmayerova, Helena

    2003-11-01

    The beta-chemokines MIP-1alpha, MIP-1beta, and RANTES inhibit HIV-1 infection of CD4+ T cells by inhibiting interactions between the virus and CCR5 receptors. However, while beta-chemokine-mediated inhibition of HIV-1 infection of primary lymphocytes is well documented, conflicting results have been obtained using primary macrophages as the virus target. Here, we show that the beta-chemokine RANTES inhibits virus entry into both cellular targets of the virus, lymphocytes and macrophages. However, while virus entry is inhibited at the moment of infection in both cell types, the amount of virus progeny is lowered only in lymphocytes. In macrophages, early-entry restriction is lost during long-term cultivation, and the amount of virus produced by RANTES-treated macrophages is similar to the untreated cultures, suggesting an enhanced virus replication. We further show that at least two distinct cellular responses to RANTES treatment in primary lymphocytes and macrophages contribute to this phenomenon. In lymphocytes, exposure to RANTES significantly increases the pool of inhibitory beta-chemokines through intracellular signals that result in increased production of MIP-1alpha and MIP-1beta, thereby amplifying the antiviral effects of RANTES. In macrophages this amplification step does not occur. In fact, RANTES added to the macrophages is efficiently cleared from the culture, without inducing synthesis of beta-chemokines. Our results demonstrate dichotomous effects of RANTES on HIV-1 entry at the moment of infection, and on production and spread of virus progeny in primary macrophages. Since macrophages serve as a reservoir of HIV-1, this may contribute to the failure of endogenous chemokines to successfully eradicate the virus.

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

    PubMed

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

    2015-06-01

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

  12. Bresol inhibits phosphodiesterase 4 gene expression and modulates the levels of select mediators of inflammation in human monocytic cells.

    PubMed

    Sandeep Varma, R; Ashok, G; Vidyashankar, S; Nandakumar, K S; Patki, P S

    2011-01-01

    Bresol-a poly-herbal formulation, has been reported to be effective against bronchial asthma and allergic rhinitis in children. In vivo studies have supported the anti-histaminic and anti-anaphylactic action of bresol. However, the mechanism of action of bresol in modulation of inflammation has not been studied at the cellular and molecular level. The present study was aimed to elucidate the mechanism(s) of action of bresol at the cellular and molecular levels, using human monocyte leukemia cells. The effects of bresol on phosphodiesterase 4B (PDE4B) gene expression were analyzed using human monocytic U937 leukemia cells. The ability of bresol to stimulate cAMP formation in these cells, as well as its effects on mediators of inflammation like tumor necrosis factor-α (TNFα), nitric oxide (NO), and cycloxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated U937 cells, were also studied. The results here indicated that bresol exhibited potential anti-inflammatory properties by inhibiting LPS-induced PDE4B gene expression in the cells. Bresol also dose dependently activated cAMP formation, and inhibited TNFα, NO, as well as COX-2 formation in the LPS-stimulated cells. Based upon the results, we concluded that the reported anti-inflammatory activity of bresol might be attributed to its abilities to inhibit PDE4B and thus elevate cAMP levels in human monocytes. The anti-inflammatory effects of bresol might also be a result of the capacity of bresol to modulate the formation of TNFα, NO, and COX-2 in monocytes.

  13. Monodispersed calcium carbonate nanoparticles modulate local pH and inhibit tumor growth in vivo

    NASA Astrophysics Data System (ADS)

    Som, Avik; Raliya, Ramesh; Tian, Limei; Akers, Walter; Ippolito, Joseph E.; Singamaneni, Srikanth; Biswas, Pratim; Achilefu, Samuel

    2016-06-01

    The acidic extracellular environment of tumors potentiates their aggressiveness and metastasis, but few methods exist to selectively modulate the extracellular pH (pHe) environment of tumors. Transient flushing of biological systems with alkaline fluids or proton pump inhibitors is impractical and nonselective. Here we report a nanoparticles-based strategy to intentionally modulate the pHe in tumors. Biochemical simulations indicate that the dissolution of calcium carbonate nanoparticles (nano-CaCO3) in vivo increases pH asymptotically to 7.4. We developed two independent facile methods to synthesize monodisperse non-doped vaterite nano-CaCO3 with distinct size range between 20 and 300 nm. Using murine models of cancer, we demonstrate that the selective accumulation of nano-CaCO3 in tumors increases tumor pH over time. The associated induction of tumor growth stasis is putatively interpreted as a pHe increase. This study establishes an approach to prepare nano-CaCO3 over a wide particle size range, a formulation that stabilizes the nanomaterials in aqueous solutions, and a pH-sensitive nano-platform capable of modulating the acidic environment of cancer for potential therapeutic benefits.The acidic extracellular environment of tumors potentiates their aggressiveness and metastasis, but few methods exist to selectively modulate the extracellular pH (pHe) environment of tumors. Transient flushing of biological systems with alkaline fluids or proton pump inhibitors is impractical and nonselective. Here we report a nanoparticles-based strategy to intentionally modulate the pHe in tumors. Biochemical simulations indicate that the dissolution of calcium carbonate nanoparticles (nano-CaCO3) in vivo increases pH asymptotically to 7.4. We developed two independent facile methods to synthesize monodisperse non-doped vaterite nano-CaCO3 with distinct size range between 20 and 300 nm. Using murine models of cancer, we demonstrate that the selective accumulation of nano-CaCO3

  14. Adaptability to pain is associated with potency of local pain inhibition, but not conditioned pain modulation: a healthy human study.

    PubMed

    Zheng, Zhen; Wang, Kelun; Yao, Dongyuan; Xue, Charlie C L; Arendt-Nielsen, Lars

    2014-05-01

    This study investigated the relationship between pain sensitivity, adaptability, and potency of endogenous pain inhibition, including conditioned pain modulation (CPM) and local pain inhibition. Forty-one healthy volunteers (20 male, 21 female) received conditioning stimulation (CS) over 2 sessions in a random order: tonic heat pain (46 °C) on the right leg for 7 minutes and cold pressor pain (1 °C to 4 °C) on the left hand for 5 minutes. Participants rated the intensity of pain continuously using a 0 to 10 electronic visual analogue scale. The primary outcome measures were pressure pain thresholds (PPT) measured at the heterotopic and homotopic location to the CS sites before, during, and 20 minutes after CS. Two groups of participants, pain adaptive and pain nonadaptive, were identified based on their response to pain in the cold pressor test. Pain-adaptive participants showed a pain reduction between peak pain and pain at end of the test by at least 2 of 10 (n=16); whereas the pain-nonadaptive participants reported unchanged peak pain during 5-minute CS (n=25). Heterotopic PPTs during the CS did not differ between the 2 groups. However, increased homotopic PPTs measured 20 minutes after CS correlated with the amount of pain reduction during CS. These results suggest that individual sensitivity and adaptability to pain does not correlate with the potency of CPM. Adaptability to pain is associated with longer-lasting local pain inhibition.

  15. Splenectomy inhibits non-small cell lung cancer growth by modulating anti-tumor adaptive and innate immune response

    PubMed Central

    Levy, Liran; Mishalian, Inbal; Bayuch, Rachel; Zolotarov, Lida; Michaeli, Janna; Fridlender, Zvi G

    2015-01-01

    It has been shown that inhibitors of the immune system reside in the spleen and inhibit the endogenous antitumor effects of the immune system. We hypothesized that splenectomy would inhibit the growth of relatively large non-small lung cancer (NSCLC) tumors by modulating the systemic inhibition of the immune system, and in particular Myeloid Derived Suppressor Cells (MDSC). The effect of splenectomy was evaluated in several murine lung cancer models. We found that splenectomy reduces tumor growth and the development of lung metastases, but only in advanced tumors. In immune-deficient NOD-SCID mice the effect of splenectomy on tumor growth and metastatic spread disappeared. Splenectomy significantly reduced the presence of MDSC, and especially monocytic-MDSC in the circulation and inside the tumor. Specific reduction of the CCR2+ subset of monocytic MDSC was demonstrated, and the importance of the CCL2-CCR2 axis was further shown by a marked reduction in CCL2 following splenectomy. These changes were followed by changes in the macrophages contents of the tumors to become more antitumorigenic, and by increased activation of CD8+ Cytotoxic T-cells (CTL). By MDSC depletion, and adoptive transfer of MDSCs, we demonstrated that the effect of splenectomy on tumor growth was substantially mediated by MDSC cells. We conclude that the spleen is an important contributor to tumor growth and metastases, and that splenectomy can blunt this effect by depletion of MDSC, changing the amount and characteristics of myeloid cells and enhancing activation of CTL. PMID:26137413

  16. Monodispersed calcium carbonate nanoparticles modulate local pH and inhibit tumor growth in vivo.

    PubMed

    Som, Avik; Raliya, Ramesh; Tian, Limei; Akers, Walter; Ippolito, Joseph E; Singamaneni, Srikanth; Biswas, Pratim; Achilefu, Samuel

    2016-07-01

    The acidic extracellular environment of tumors potentiates their aggressiveness and metastasis, but few methods exist to selectively modulate the extracellular pH (pHe) environment of tumors. Transient flushing of biological systems with alkaline fluids or proton pump inhibitors is impractical and nonselective. Here we report a nanoparticles-based strategy to intentionally modulate the pHe in tumors. Biochemical simulations indicate that the dissolution of calcium carbonate nanoparticles (nano-CaCO3) in vivo increases pH asymptotically to 7.4. We developed two independent facile methods to synthesize monodisperse non-doped vaterite nano-CaCO3 with distinct size range between 20 and 300 nm. Using murine models of cancer, we demonstrate that the selective accumulation of nano-CaCO3 in tumors increases tumor pH over time. The associated induction of tumor growth stasis is putatively interpreted as a pHe increase. This study establishes an approach to prepare nano-CaCO3 over a wide particle size range, a formulation that stabilizes the nanomaterials in aqueous solutions, and a pH-sensitive nano-platform capable of modulating the acidic environment of cancer for potential therapeutic benefits. PMID:26745389

  17. Monodispersed calcium carbonate nanoparticles modulate local pH and inhibit tumor growth in vivo.

    PubMed

    Som, Avik; Raliya, Ramesh; Tian, Limei; Akers, Walter; Ippolito, Joseph E; Singamaneni, Srikanth; Biswas, Pratim; Achilefu, Samuel

    2016-07-01

    The acidic extracellular environment of tumors potentiates their aggressiveness and metastasis, but few methods exist to selectively modulate the extracellular pH (pHe) environment of tumors. Transient flushing of biological systems with alkaline fluids or proton pump inhibitors is impractical and nonselective. Here we report a nanoparticles-based strategy to intentionally modulate the pHe in tumors. Biochemical simulations indicate that the dissolution of calcium carbonate nanoparticles (nano-CaCO3) in vivo increases pH asymptotically to 7.4. We developed two independent facile methods to synthesize monodisperse non-doped vaterite nano-CaCO3 with distinct size range between 20 and 300 nm. Using murine models of cancer, we demonstrate that the selective accumulation of nano-CaCO3 in tumors increases tumor pH over time. The associated induction of tumor growth stasis is putatively interpreted as a pHe increase. This study establishes an approach to prepare nano-CaCO3 over a wide particle size range, a formulation that stabilizes the nanomaterials in aqueous solutions, and a pH-sensitive nano-platform capable of modulating the acidic environment of cancer for potential therapeutic benefits.

  18. GABAA-Mediated Inhibition Modulates Stimulus-Specific Adaptation in the Inferior Colliculus

    PubMed Central

    Pérez-González, David; Hernández, Olga; Covey, Ellen; Malmierca, Manuel S.

    2012-01-01

    The ability to detect novel sounds in a complex acoustic context is crucial for survival. Neurons from midbrain through cortical levels adapt to repetitive stimuli, while maintaining responsiveness to rare stimuli, a phenomenon called stimulus-specific adaptation (SSA). The site of origin and mechanism of SSA are currently unknown. We used microiontophoretic application of gabazine to examine the role of GABAA-mediated inhibition in SSA in the inferior colliculus, the midbrain center for auditory processing. We found that gabazine slowed down the process of adaptation to high probability stimuli but did not abolish it, with response magnitude and latency still depending on the probability of the stimulus. Blocking GABAA receptors increased the firing rate to high and low probability stimuli, but did not completely equalize the responses. Together, these findings suggest that GABAA-mediated inhibition acts as a gain control mechanism that enhances SSA by modifying the responsiveness of the neuron. PMID:22479591

  19. Triethylenetetramine modulates polyamine and energy metabolism and inhibits cancer cell proliferation.

    PubMed

    Hyvönen, Mervi T; Ucal, Sebahat; Pasanen, Markku; Peräniemi, Sirpa; Weisell, Janne; Khomutov, Maxim; Khomutov, Alex R; Vepsäläinen, Jouko; Alhonen, Leena; Keinänen, Tuomo A

    2016-05-15

    Polyamine metabolism is an attractive anticancer drug target, since polyamines are absolutely required for cellular proliferation, and increased levels of polyamines and their biosynthetic enzyme ornithine decarboxylase (ODC) are associated with cancer. Triethylenetetramine (TETA) is a charge-deficient isosteric analogue of the polyamine spermidine (Spd) and a Cu(II)-chelating compound used for the treatment of Wilson's disease, and it has been implicated as a potential anticancer therapeutic drug. In the present study, we studied the effects of TETA in comparison with two other Cu(II)-chelators, D-penicillamine (PA) and tetrathiomolybdate (TTM), on polyamine metabolism in DU145 prostate carcinoma, MCF-7 breast carcinoma and JEG-3 choriocarcinoma cells. TETA induced antizyme, down-regulated ODC and inhibited [(14)C] Spd uptake. Moreover, it completely prevented α-difluoromethylornithine (DFMO)-induced increase in [(14)C] Spd uptake, and inhibited [(14)C] putrescine (Put) uptake and ODC activity in vivo Seven-day treatment of DU145 cells with TETA caused growth cessation by reducing intracellular polyamine levels and suppressing the formation of hypusinated eukaryotic translation initiation factor 5A (eIF5A). TETA or its N-acetylated metabolites also inhibited spermine (Spm), diamine and semicarbazide-sensitive amine oxidases and decreased the level of intracellular reactive oxygen species. Moreover, TETA inhibited the utilization of Put as energy source via the tricarboxylic acid (TCA) cycle, as indicated by decreased production of (14)CO2 from [(14)C] Put. These results indicate that TETA attacks multiple proven anticancer drug targets not attributed to copper chelation, which warrants further studies to reveal its potential in cancer chemoprevention and cure. PMID:27001865

  20. Population Density Modulates Drug Inhibition and Gives Rise to Potential Bistability of Treatment Outcomes for Bacterial Infections

    PubMed Central

    Maltas, Jeff; Brumm, Peter; Wood, Kevin B.

    2016-01-01

    The inoculum effect (IE) is an increase in the minimum inhibitory concentration (MIC) of an antibiotic as a function of the initial size of a microbial population. The IE has been observed in a wide range of bacteria, implying that antibiotic efficacy may depend on population density. Such density dependence could have dramatic effects on bacterial population dynamics and potential treatment strategies, but explicit measures of per capita growth as a function of density are generally not available. Instead, the IE measures MIC as a function of initial population size, and population density changes by many orders of magnitude on the timescale of the experiment. Therefore, the functional relationship between population density and antibiotic inhibition is generally not known, leaving many questions about the impact of the IE on different treatment strategies unanswered. To address these questions, here we directly measured real-time per capita growth of Enterococcus faecalis populations exposed to antibiotic at fixed population densities using multiplexed computer-automated culture devices. We show that density-dependent growth inhibition is pervasive for commonly used antibiotics, with some drugs showing increased inhibition and others decreased inhibition at high densities. For several drugs, the density dependence is mediated by changes in extracellular pH, a community-level phenomenon not previously linked with the IE. Using a simple mathematical model, we demonstrate how this density dependence can modulate population dynamics in constant drug environments. Then, we illustrate how time-dependent dosing strategies can mitigate the negative effects of density-dependence. Finally, we show that these density effects lead to bistable treatment outcomes for a wide range of antibiotic concentrations in a pharmacological model of antibiotic treatment. As a result, infections exceeding a critical density often survive otherwise effective treatments. PMID:27764095

  1. Modulation of crystal formation by bone phosphoproteins: structural specificity of the osteopontin-mediated inhibition of hydroxyapatite formation.

    PubMed

    Hunter, G K; Kyle, C L; Goldberg, H A

    1994-06-15

    Osteopontin is a phosphorylated sialoprotein containing a conserved sequence of contiguous aspartic acid residues. This protein is expressed at high levels in mineralized tissues and has previously been shown to inhibit the in vitro formation of hydroxyapatite (HA). In the present study, protein modification and model compound studies have been used to identify the structural features of osteopontin that are responsible for its crystal-modulating properties. Using metastable calcium phosphate solutions buffered by autotitration, osteopontin caused half-maximal inhibition of HA formation at a concentration (IC50) of 0.06 microgram/ml. The hen egg yolk phosphoprotein phosvitin was a much weaker inhibitor, while dextran sulphate had no effect. The synthetic polypeptide poly(aspartic acid) was almost as effective an inhibitor of HA formation as osteopontin (IC50 0.11 microgram/ml), whereas poly(glutamic acid) was more than a thousand times less potent (IC50 155 micrograms/ml). In a steady-state agarose gel system, much higher polypeptide concentrations were required for inhibition of HA formation, but a similar relative order of inhibitory effectiveness was observed. Treatment of osteopontin with alkaline phosphatase removed 84% of the covalently bound phosphate and reduced its HA-inhibiting activity by more than 40-fold. Treatment with glycine ethyl ester in the presence of carbodi-imide modified 86% of the carboxylate groups in osteopontin and reduced its inhibitory activity by 6-fold. These findings indicate that osteopontin is a potent inhibitor of HA formation. This activity requires phosphate and carboxylate groups, possibly including the conserved sequence of contiguous aspartic acid residues. Osteopontin may act as an inhibitor of phase separation in physiological fluids of high supersaturation.

  2. Predicting Modulation in Corticomotor Excitability and in Transcallosal Inhibition in Response to Anodal Transcranial Direct Current Stimulation

    PubMed Central

    Davidson, Travis W.; Bolic, Miodrag; Tremblay, François

    2016-01-01

    Introduction: Responses to neuromodulatory protocols based either on transcranial direct current stimulation (tDCS) or transcranial magnetic stimulation (TMS) are known to be highly variable between individuals. In this study, we examined whether variability of responses to anodal tDCS (a-tDCS) could be predicted from individual differences in the ability to recruit early or late indirect waves (I-waves), as reflected in latency differences of motor evoked potentials (MEPs) evoked by TMS of different coil orientation. Methods: Participants (n = 20) first underwent TMS to measure latency of MEPs elicited at different coil orientations (i.e., PA, posterior-anterior; AP, anterior-posterior; LM, latero-medial). Then, participants underwent a-tDCS (20 min @ 2 mA) targeting the primary motor cortex of the contralateral preferred hand (right, n = 18). Individual responses to a-tDCS were determined by monitoring changes in MEP amplitude at rest and in the duration of the contralateral silent period (cSP) and ipsilateral silent period (iSP) during contraction; the latter providing an index of the latency and duration of transcallosal inhibition (LTI and DTI). Results: Consistent with previous reports, individual responses to a-tDCS were highly variable when expressed in terms of changes in MEP amplitude or in cSP duration with ~50% of the participants showing either little or no modulation. In contrast, individual variations in measures of transcallosal inhibition were less variable, allowing detection of significant after-effects. The reduced LTI and prolonged DTI observed post-tDCS were indicative of an enhanced excitability of the transcallosal pathway in the stimulated hemisphere. In terms of predictions, AP-LM latency differences proved to be good predictors of responses to a-tDCS when considering MEP modulation. Conclusion: The present results corroborate the predictive value of latency differences derived from TMS to determine who is likely to express

  3. Modulation of NMDA receptor function by inhibition of D-amino acid oxidase in rodent brain.

    PubMed

    Strick, Christine A; Li, Cheryl; Scott, Liam; Harvey, Brian; Hajós, Mihály; Steyn, Stefanus J; Piotrowski, Mary A; James, Larry C; Downs, James T; Rago, Brian; Becker, Stacey L; El-Kattan, Ayman; Xu, Youfen; Ganong, Alan H; Tingley, F David; Ramirez, Andres D; Seymour, Patricia A; Guanowsky, Victor; Majchrzak, Mark J; Fox, Carol B; Schmidt, Christopher J; Duplantier, Allen J

    2011-01-01

    Observations that N-Methyl-D-Aspartate (NMDA) antagonists produce symptoms in humans that are similar to those seen in schizophrenia have led to the current hypothesis that schizophrenia might result from NMDA receptor hypofunction. Inhibition of D-amino acid oxidase (DAAO), the enzyme responsible for degradation of D-serine, should lead to increased levels of this co-agonist at the NMDA receptor, and thereby provide a therapeutic approach to schizophrenia. We have profiled some of the preclinical biochemical, electrophysiological, and behavioral consequences of administering potent and selective inhibitors of DAAO to rodents to begin to test this hypothesis. Inhibition of DAAO activity resulted in a significant dose and time dependent increase in D-serine only in the cerebellum, although a time delay was observed between peak plasma or brain drug concentration and cerebellum D-serine response. Pharmacokinetic/pharmacodynamic (PK/PD) modeling employing a mechanism-based indirect response model was used to characterize the correlation between free brain drug concentration and D-serine accumulation. DAAO inhibitors had little or no activity in rodent models considered predictive for antipsychotic activity. The inhibitors did, however, affect cortical activity in the Mescaline-Induced Scratching model, produced a modest but significant increase in NMDA receptor-mediated synaptic currents in primary neuronal cultures from rat hippocampus, and resulted in a significant increase in evoked hippocampal theta rhythm, an in vivo electrophysiological model of hippocampal activity. These findings demonstrate that although DAAO inhibition did not cause a measurable increase in D-serine in forebrain, it did affect hippocampal and cortical activity, possibly through augmentation of NMDA receptor-mediated currents.

  4. Delphinidin inhibits cell proliferation and invasion via modulation of Met receptor phosphorylation

    SciTech Connect

    Syed, Deeba N.; Afaq, Farrukh; Sarfaraz, Sami; Khan, Naghma; Kedlaya, Rajendra; Setaluri, Vijayasaradhi; Mukhtar, Hasan

    2008-08-15

    The HGF/Met signaling pathway is deregulated in majority of cancers and is associated with poor prognosis in breast cancer. Delphinidin, present in pigmented fruits and vegetables possesses potent anti-oxidant, anti-inflammatory and anti-angiogenic properties. Here, we assessed the anti-proliferative and anti-invasive effects of delphinidin on HGF-mediated responses in the immortalized MCF-10A breast cell line. Treatment of cells with delphinidin prior to exposure to exogenous HGF resulted in the inhibition of HGF-mediated (i) tyrosyl-phosphorylation and increased expression of Met receptor, (ii) phosphorylation of downstream regulators such as FAK and Src and (iii) induction of adaptor proteins including paxillin, Gab-1 and GRB-2. In addition, delphinidin treatment resulted in significant inhibition of HGF-activated (i) Ras-ERK MAPKs and (ii) PI3K/AKT/mTOR/p70S6K pathways. Delphinidin was found to repress HGF-activated NF{kappa}B transcription with a decrease in (i) phosphorylation of IKK{alpha}/{beta} and I{kappa}B{alpha}, and (ii) activation and nuclear translocation of NF{kappa}B/p65. Inhibition of HGF-mediated membrane translocation of PKC{alpha} as well as decreased phosphorylation of STAT3 was further observed in delphinidin treated cells. Finally, decreased cell viability of Met receptor expressing breast cancer cells treated with delphinidin argues for a potential role of the agent in the prevention of HGF-mediated activation of various signaling pathways implicated in breast cancer.

  5. Thiol-modulated mechanisms of the cytotoxicity of thimerosal and inhibition of DNA topoisomerase II alpha.

    PubMed

    Wu, Xing; Liang, Hong; O'Hara, Kimberley A; Yalowich, Jack C; Hasinoff, Brian B

    2008-02-01

    Thimerosal is an organic mercury compound that is widely used as a preservative in vaccines and other solution formulations. The use of thimerosal has caused concern about its ability to cause neurological abnormalities due to mercury accumulation during a normal schedule of childhood vaccinations. While the chemistry and the biological effects of methylmercury have been well-studied, those of thimerosal have not. Thimerosal reacted rapidly with cysteine, GSH, human serum albumin, and single-stranded DNA to form ethylmercury adducts that were detectable by mass spectrometry. These results indicated that thimerosal would be quickly metabolized in vivo because of its reactions with protein and nonprotein thiols. Thimerosal also potently inhibited the decatenation activity of DNA topoisomerase II alpha, likely through reaction with critical free cysteine thiol groups. Thimerosal, however, did not act as a topoisomerase II poison and the lack of cross-resistance with a K562 cell line with a decreased level of topoisomerase II alpha (K/VP.5 cells) suggested that inhibition of topoisomerase II alpha was not a significant mechanism for the inhibition of cell growth. Depletion of intracellular GSH with buthionine sulfoximine treatment greatly increased the K562 cell growth inhibitory effects of thimerosal, which showed that intracellular glutathione had a major role in protecting cells from thimerosal. Pretreatment of thimerosal with glutathione did not, however, change its K562 cell growth inhibitory effects, a result consistent with the rapid exchange of the ethylmercury adduct among various thiol-containing cellular reactants. Thimerosal-induced single and double strand breaks in K562 cells were consistent with a rapid induction of apoptosis. In conclusion, these studies have elucidated some of the chemistry and biological activities of the interaction of thimerosal with topoisomerase II alpha and protein and nonprotein thiols and with DNA.

  6. Almond Skin Inhibits HSV-2 Replication in Peripheral Blood Mononuclear Cells by Modulating the Cytokine Network.

    PubMed

    Arena, Adriana; Bisignano, Carlo; Stassi, Giovanna; Filocamo, Angela; Mandalari, Giuseppina

    2015-01-01

    We have investigated the effect of almond skin extracts on the production of pro-inflammatory and anti-inflammatory cytokines in human peripheral blood mononuclear cells (PBMCs). PBMCs were either infected or not by herpes simplex virus type 2 (HSV-2), with and without prior treatment with almond skin extracts. Production of IL-17 induced by HSV-2 was inhibited by natural skins (NS) treatment. NS triggered PBMC in releasing IFN-α, IFN-γ and IL-4 in cellular supernatants. These results may explain the antiviral potential of almond skins.

  7. Folic Acid Inhibits Amyloid β-Peptide Production through Modulating DNA Methyltransferase Activity in N2a-APP Cells.

    PubMed

    Li, Wen; Jiang, Mingyue; Zhao, Shijing; Liu, Huan; Zhang, Xumei; Wilson, John X; Huang, Guowei

    2015-10-20

    Alzheimer's disease (AD) is a common neurodegenerative disease resulting in progressive dementia, and is a principal cause of dementia among older adults. Folate acts through one-carbon metabolism to support the methylation of multiple substrates. We hypothesized that folic acid supplementation modulates DNA methyltransferase (DNMT) activity and may alter amyloid β-peptide (Aβ) production in AD. Mouse Neuro-2a cells expressing human APP695 were incubated with folic acid (2.8-40 μmol/L), and with or without zebularine (the DNMT inhibitor). DNMT activity, cell viability, Aβ and DNMTs expression were then examined. The results showed that folic acid stimulated DNMT gene and protein expression, and DNMT activity. Furthermore, folic acid decreased Aβ protein production, whereas inhibition of DNMT activity by zebularine increased Aβ production. The results indicate that folic acid induces methylation potential-dependent DNMT enzymes, thereby attenuating Aβ production.

  8. Modulation of urokinase plasminogen activator system by poly(ADP-ribose)polymerase-1 inhibition.

    PubMed

    Madunić, Josip; Antica, Mariastefania; Cvjetko, Petra; Požgaj, Lidija; Matulić, Maja

    2016-08-01

    The urokinase plasminogen activator (uPA) system is a complex regulator of extracellular proteolysis which is involved in various physiological and pathological processes. The major components of this system are the serine protease uPA, two inhibitors PAI-1 and PAI-2, and the receptor uPAR. It has been previously shown by several groups that the uPA system has an important role in cancer progression and therefore its possible prognostic and therapeutic value has been evaluated. The aim of this study is to tackle the role of poly(ADP-ribosyl)ation in the induction of uPA activity in a glioblastoma cell line, A1235. This cell line is sensitive to alkylation damage and is a model for drug treatment. The components of the uPA system and the level of DNA damage were analyzed after alkylation agent treatment in combination with poly(ADP-ribose)polymerase-1 (PARP-1) inhibition. Here we show that the increase in uPA activity results from the net balance change between uPA and its inhibitor at mRNA level. Further, PARP-1 inhibition exerts its influence on uPA activity through DNA damage increase. Involvement of several signaling pathways, as well as cell specific regulation influencing the uPA system are discussed.

  9. Inhibition of HDAC1 and DNMT1 Modulate RGS10 Expression and Decrease Ovarian Cancer Chemoresistance

    PubMed Central

    Cacan, Ercan; Ali, Mourad W.; Boyd, Nathaniel H.; Hooks, Shelley B.; Greer, Susanna F.

    2014-01-01

    RGS10 is an important regulator of cell survival and chemoresistance in ovarian cancer. We recently showed that RGS10 transcript expression is suppressed during acquired chemoresistance in ovarian cancer. The suppression of RGS10 is due to DNA hypermethylation and histone deacetylation, two important mechanisms that contribute to silencing of tumor suppressor genes during cancer progression. Here, we fully investigate the molecular mechanisms of epigenetic silencing of RGS10 expression in chemoresistant A2780-AD ovarian cancer cells. We identify two important epigenetic regulators, HDAC1 and DNMT1, that exhibit aberrant association with RGS10 promoters in chemoresistant ovarian cancer cells. Knockdown of HDAC1 or DNMT1 expression, and pharmacological inhibition of DNMT or HDAC enzymatic activity, significantly increases RGS10 expression and cisplatin-mediated cell death. Finally, DNMT1 knock down also decreases HDAC1 binding to the RGS10 promoter in chemoresistant cells, suggesting HDAC1 recruitment to RGS10 promoters requires DNMT1 activity. Our results suggest that HDAC1 and DNMT1 contribute to the suppression of RGS10 during acquired chemoresistance and support inhibition of HDAC1 and DNMT1 as an adjuvant therapeutic approach to overcome ovarian cancer chemoresistance. PMID:24475290

  10. Prestimulus neural oscillations inhibit visual perception via modulation of response gain.

    PubMed

    Chaumon, Maximilien; Busch, Niko A

    2014-11-01

    The ongoing state of the brain radically affects how it processes sensory information. How does this ongoing brain activity interact with the processing of external stimuli? Spontaneous oscillations in the alpha range are thought to inhibit sensory processing, but little is known about the psychophysical mechanisms of this inhibition. We recorded ongoing brain activity with EEG while human observers performed a visual detection task with stimuli of different contrast intensities. To move beyond qualitative description, we formally compared psychometric functions obtained under different levels of ongoing alpha power and evaluated the inhibitory effect of ongoing alpha oscillations in terms of contrast or response gain models. This procedure opens the way to understanding the actual functional mechanisms by which ongoing brain activity affects visual performance. We found that strong prestimulus occipital alpha oscillations-but not more anterior mu oscillations-reduce performance most strongly for stimuli of the highest intensities tested. This inhibitory effect is best explained by a divisive reduction of response gain. Ongoing occipital alpha oscillations thus reflect changes in the visual system's input/output transformation that are independent of the sensory input to the system. They selectively scale the system's response, rather than change its sensitivity to sensory information.

  11. Nitric oxide signaling modulates synaptic inhibition in the superior paraolivary nucleus (SPN) via cGMP-dependent suppression of KCC2

    PubMed Central

    Yassin, Lina; Radtke-Schuller, Susanne; Asraf, Hila; Grothe, Benedikt; Hershfinkel, Michal; Forsythe, Ian D.; Kopp-Scheinpflug, Cornelia

    2014-01-01

    Glycinergic inhibition plays a central role in the auditory brainstem circuitries involved in sound localization and in the encoding of temporal action potential firing patterns. Modulation of this inhibition has the potential to fine-tune information processing in these networks. Here we show that nitric oxide (NO) signaling in the auditory brainstem (where activity-dependent generation of NO is documented) modulates the strength of inhibition by changing the chloride equilibrium potential. Recent evidence demonstrates that large inhibitory postsynaptic currents (IPSCs) in neurons of the superior paraolivary nucleus (SPN) are enhanced by a very low intracellular chloride concentration, generated by the neuronal potassium chloride co-transporter (KCC2) expressed in the postsynaptic neurons. Our data show that modulation by NO caused a 15 mV depolarizing shift of the IPSC reversal potential, reducing the strength of inhibition in SPN neurons, without changing the threshold for action potential firing. Regulating inhibitory strength, through cGMP-dependent changes in the efficacy of KCC2 in the target neuron provides a postsynaptic mechanism for rapidly controlling the inhibitory drive, without altering the timing or pattern of the afferent spike train. Therefore, this NO-mediated suppression of KCC2 can modulate inhibition in one target nucleus (SPN), without influencing inhibitory strength of other target nuclei (MSO, LSO) even though they are each receiving collaterals from the same afferent nucleus (a projection from the medial nucleus of the trapezoid body, MNTB). PMID:24987336

  12. Modulation of diamide toxicity in thermotolerant cells by inhibition of protein synthesis.

    PubMed

    Freeman, M L; Meredith, M J

    1989-08-15

    Chinese hamster ovary cells were exposed in vitro to various concentrations of diamide for 1 h at 37 degrees C. This treatment resulted in a dose dependent increase in cytotoxicity. Cells were also heated at 43 degrees C for 15 min, incubated at 37 degrees C for 3 h, and then exposed to various concentrations of diamide. This heat shock has been shown previously to trigger the synthesis of heat shock proteins and the development of thermotolerance. Further, under these experimental conditions both were inhibited if protein synthesis was inhibited by exposure to cycloheximide (M. L. Freeman et al., Radiat. Res., 112: 195-203, 1987). Diamide toxicity was diminished in cells made thermotolerant by the 43 degrees C/15-min heat shock. For example, at the highest dose used, 0.8 mM, survival increased from 0.93% to 6.1%. However, diamide toxicity was unaffected if the cells were exposed to diamide 3 h after a 43 degrees C/60 min heat shock. This latter heat shock produced significant inhibition of protein synthesis whereas the 15-min heat shock did not (M. L. Freeman et al., Cancer Res., 48: 7033-7037, 1988). Further, a 43 degrees C/15-min heat shock did not confer protection against diamide toxicity if the cells were simultaneously exposed to cycloheximide. Exposure to 0.8 mM diamide was shown to oxidize specific cellular proteins as measured by 2-dimensional thiol blotting. However, the degree of protein thiol modification was not affected by a prior heat shock. Nor did the heat shock increase the intracellular concentration of glutathione or the activity of glutathione reductase. The diamide treatment caused specific, as opposed to general, protein thiol oxidation and heat shock did not prevent this. It is hypothesized that it was the oxidation of protein thiols which led to cellular toxicity. Protein synthesis, triggered by heat shock, protected cells from the diamide toxicity without preventing protein thiol modification. These results suggest that the proteins

  13. Modulation of Prepulse Inhibition and Startle Reflex by Emotions: A Comparison between Young and Older Adults.

    PubMed

    Le Duc, Jolyanne; Fournier, Philippe; Hébert, Sylvie

    2016-01-01

    This study examined whether or not the acoustic startle response and sensorimotor gating may be modulated by emotions differentially between young and older adults. Two groups of participants (mean age Young: 24 years old; Elderly: 63.6 years old) were presented with three types of auditory stimuli (Startle alone, High or Low frequency Prepulse) while viewing pleasant, neutral, or unpleasant images. Electromyographic activity of the eyeblink response was measured. Results show that older adults displayed diminished eyeblink responses whereas younger adults displayed enhanced eyeblink responses when viewing negative images. Sensorimotor gating also differed between young and older adults, with enhanced sensorimotor gating abilities while viewing positive pictures in older adults and diminished abilities while viewing negative pictures among younger adults. These results argue in favor of a differential emotional influence on the sensorimotor abilities of young and older adults, with a positivity bias among the latter.

  14. Modulation of Prepulse Inhibition and Startle Reflex by Emotions: A Comparison between Young and Older Adults

    PubMed Central

    Le Duc, Jolyanne; Fournier, Philippe; Hébert, Sylvie

    2016-01-01

    This study examined whether or not the acoustic startle response and sensorimotor gating may be modulated by emotions differentially between young and older adults. Two groups of participants (mean age Young: 24 years old; Elderly: 63.6 years old) were presented with three types of auditory stimuli (Startle alone, High or Low frequency Prepulse) while viewing pleasant, neutral, or unpleasant images. Electromyographic activity of the eyeblink response was measured. Results show that older adults displayed diminished eyeblink responses whereas younger adults displayed enhanced eyeblink responses when viewing negative images. Sensorimotor gating also differed between young and older adults, with enhanced sensorimotor gating abilities while viewing positive pictures in older adults and diminished abilities while viewing negative pictures among younger adults. These results argue in favor of a differential emotional influence on the sensorimotor abilities of young and older adults, with a positivity bias among the latter. PMID:26941643

  15. Modulation of Prepulse Inhibition and Startle Reflex by Emotions: A Comparison between Young and Older Adults.

    PubMed

    Le Duc, Jolyanne; Fournier, Philippe; Hébert, Sylvie

    2016-01-01

    This study examined whether or not the acoustic startle response and sensorimotor gating may be modulated by emotions differentially between young and older adults. Two groups of participants (mean age Young: 24 years old; Elderly: 63.6 years old) were presented with three types of auditory stimuli (Startle alone, High or Low frequency Prepulse) while viewing pleasant, neutral, or unpleasant images. Electromyographic activity of the eyeblink response was measured. Results show that older adults displayed diminished eyeblink responses whereas younger adults displayed enhanced eyeblink responses when viewing negative images. Sensorimotor gating also differed between young and older adults, with enhanced sensorimotor gating abilities while viewing positive pictures in older adults and diminished abilities while viewing negative pictures among younger adults. These results argue in favor of a differential emotional influence on the sensorimotor abilities of young and older adults, with a positivity bias among the latter. PMID:26941643

  16. Diet-derived polyphenols inhibit angiogenesis by modulating the interleukin-6/STAT3 pathway

    SciTech Connect

    Lamy, Sylvie; Akla, Naoufal; Ouanouki, Amira; Lord-Dufour, Simon; Beliveau, Richard

    2012-08-01

    Several epidemiological studies have indicated that abundant consumption of foods from plant origin is associated with a reduced risk of developing several types of cancers. This chemopreventive effect is related to the high content of these foods in phytochemicals, such as polyphenols, that interfere with several processes involved in cancer progression including tumor cell growth, survival and angiogenesis. In addition to the low intake of plant-based foods, increased body mass and physical inactivity have recently emerged as other important lifestyle factors influencing cancer risk, leading to the generation of low-grade chronic inflammatory conditions which are a key process involved in tumor progression. The objectives of the current study are to investigate the inhibitory effects of these polyphenols on angiogenesis triggered by an inflammatory cytokine (IL-6) and to determine the mechanisms underlying this action. We found that, among the tested polyphenols, apigenin and luteolin were the most potent angiogenesis inhibitors through their inhibitory effect on the inflammatory cytokine IL-6/STAT3 pathway. These effects resulted in modulation of the activation of extracellular signal-regulated kinase-1/2 signaling triggered by IL-6, as well as in a marked reduction in the proliferation, migration and morphogenic differentiation of endothelial cells. Interestingly, these polyphenols also modulated the expression of IL-6 signal transducing receptor (IL-6R{alpha}) and the secretion of the extracellular matrix degrading enzyme MMP-2 as well as the expression of suppressor of cytokine signaling (SOCS3) protein. Overall, these results may provide important new information on the role of diet in cancer prevention.

  17. Association of anxiety with intracortical inhibition and descending pain modulation in chronic myofascial pain syndrome

    PubMed Central

    2014-01-01

    Background This study aimed to answer three questions related to chronic myofascial pain syndrome (MPS): 1) Is the motor cortex excitability, as assessed by transcranial magnetic stimulation parameters (TMS), related to state-trait anxiety? 2) Does anxiety modulate corticospinal excitability changes after evoked pain by Quantitative Sensory Testing (QST)? 3) Does the state-trait anxiety predict the response to pain evoked by QST if simultaneously receiving a heterotopic stimulus [Conditional Pain Modulation (CPM)]? We included females with chronic MPS (n = 47) and healthy controls (n = 11), aged 19 to 65 years. Motor cortex excitability was assessed by TMS, and anxiety was assessed based on the State-Trait Anxiety Inventory. The disability related to pain (DRP) was assessed by the Profile of Chronic Pain scale for the Brazilian population (B:PCP:S), and the psychophysical pain measurements were measured by the QST and CPM. Results In patients, trait-anxiety was positively correlated to intracortical facilitation (ICF) at baseline and after QST evoked pain (β = 0.05 and β = 0.04, respectively) and negatively correlated to the cortical silent period (CSP) (β = -1.17 and β = -1.23, respectively) (P <0.05 for all comparisons). After QST evoked pain, the DRP was positively correlated to ICF (β = 0.02) (P < 0.05). Pain scores during CPM were positively correlated with trait-anxiety when it was concurrently with high DRP (β = 0.39; P = 0.02). Controls’ cortical excitability remained unchanged after QST. Conclusions These findings suggest that, in chronic MPS, the imbalance between excitatory and inhibitory descending systems of the corticospinal tract is associated with higher trait-anxiety concurrent with higher DRP. PMID:24645677

  18. Relevance of drug metabolizing enzyme activity modulation by tea polyphenols in the inhibition of esophageal tumorigenesis.

    PubMed

    Maliakal, Pius; Sankpal, Umesh T; Basha, Riyaz; Maliakal, Cima; Ledford, Andrea; Wanwimolruk, Sompon

    2011-09-01

    Tea is a popular, socially accepted, drink that is enjoyed by millions of people. A growing body of evidence suggests that moderate consumption of tea may protect against several forms of cancer. It is also known that bioactivation of precarcinogens and detoxification of ultimate carcinogens is carried out mainly by drug metabolizing enzymes such as cytochrome P450 (CYP). The present study investigates the effect of tea consumption on modulating CYP and phase II conjugating enzymes, and their association in the chemopreventive effect against esophageal tumorigenesis using both in vitro and in vivo techniques. Female Wistar rats were given aqueous solutions (2% w/v) of six different teas, standard green tea extract (GTE) (0.5% w/v), and dandelion tea (2% w/v) as the sole source of fluid for two weeks prior to and during the entire period of tumour induction (12 weeks). Animals were gavaged with 0.5 mg/kg N-nitrosomethylbenzylamine (NMBA) twice weekly for 12 weeks for esophageal tumor induction and the activities of different CYP isoforms and phase II enzymes were determined in the liver microsomes or cytosols. GTE, green tea and Dandelion tea caused decrease in tumour multiplication, tumour size and tumour volume; however, none of these tea preparations altered tumour incidence. No appreciable changes in drug metabolizing enzyme activity were observed in the treatment groups. Thus, the modulations in the activities of CYP 1A1/ 1A2 and CYP2E enzymes, by pre-treatment with green and dandelion teas, observed in our earlier experiments, seem to be compensated by the tumor inducing agent, NMBA. The balance between phase I carcinogen-activating enzymes and phase II detoxifying enzymes could be important in determining the risk of developing chemically-induced cancer and the present study in conjunction with the previous observations suggest a possible role of drug metabolizing enzymes in the anticancer effect of tea.

  19. There is a time and a place for everything: bidirectional modulations of latent inhibition by time-induced context differentiation.

    PubMed

    Lubow, R E; De la Casa, L G

    2005-10-01

    Latent inhibition (LI) is defined as poorer evidence of learning with a stimulus that previously was presented without consequence, as compared with a novel or previously attended stimulus. The present article reviews the evidence, mostly from three-stage conditioned taste aversion studies (preexposure, conditioning, and test), that LI can be either attenuated or enhanced depending on the length of the retention interval between conditioning and test and where that interval was spent. Time-induced reduction in LI is observed when the interval context is the same as that of the preexposure, conditioning, and test stages. Super-LI is obtained when a long retention interval is spent in a context that is different from that of the other stages. The differential modulations of LI appear to be the result of the strengthening of primacy effects (i.e., first training disproportionately stronger than subsequent training) by long-interval different contexts, thereby producing super-LI, and the reversal of this effect by long-interval same contexts, thereby producing attenuated LI. The bidirectional effects of time/ context modulations on LI, unaccounted for by current learning theories, are explained, in part, by a time-induced context differentiation process. Implications for theories of LI, learning, and, memory are discussed.

  20. Silent information regulator 1 modulator resveratrol increases brain lactate production and inhibits mitochondrial metabolism, whereas SRT1720 increases oxidative metabolism.

    PubMed

    Rowlands, Benjamin D; Lau, Chew Ling; Ryall, James G; Thomas, Donald S; Klugmann, Matthias; Beart, Philip M; Rae, Caroline D

    2015-07-01

    Silent information regulators (SIRTs) have been shown to deacetylate a range of metabolic enzymes, including those in glycolysis and the Krebs cycle, and thus alter their activity. SIRTs require NAD(+) for their activity, linking cellular energy status to enzyme activity. To examine the impact of SIRT1 modulation on oxidative metabolism, this study tests the effect of ligands that are either SIRT-activating compounds (resveratrol and SRT1720) or SIRT inhibitors (EX527) on the metabolism of (13)C-enriched substrates by guinea pig brain cortical tissue slices with (13)C and (1)H nuclear magnetic resonance spectroscopy. Resveratrol increased lactate labeling but decreased incorporation of (13)C into Krebs cycle intermediates, consistent with effects on AMPK and inhibition of the F0/F1-ATPase. By testing with resveratrol that was directly applied to astrocytes with a Seahorse analyzer, increased glycolytic shift and increased mitochondrial proton leak resulting from interactions of resveratrol with the mitochondrial electron transport chain were revealed. SRT1720, by contrast, stimulated incorporation of (13)C into Krebs cycle intermediates and reduced incorporation into lactate, although the inhibitor EX527 paradoxically also increased Krebs cycle (13)C incorporation. In summary, the various SIRT1 modulators show distinct acute effects on oxidative metabolism. The strong effects of resveratrol on the mitochondrial respiratory chain and on glycolysis suggest that caution should be used in attempts to increase bioavailability of this compound in the CNS.

  1. Light-Limited Growth Rate Modulates Nitrate Inhibition of Dinitrogen Fixation in the Marine Unicellular Cyanobacterium Crocosphaera watsonii

    PubMed Central

    Garcia, Nathan S.; Hutchins, David A.

    2014-01-01

    Biological N2 fixation is the dominant supply of new nitrogen (N) to the oceans, but is often inhibited in the presence of fixed N sources such as nitrate (NO3−). Anthropogenic fixed N inputs to the ocean are increasing, but their effect on marine N2 fixation is uncertain. Thus, global estimates of new oceanic N depend on a fundamental understanding of factors that modulate N source preferences by N2-fixing cyanobacteria. We examined the unicellular diazotroph Crocosphaera watsonii (strain WH0003) to determine how the light-limited growth rate influences the inhibitory effects of fixed N on N2 fixation. When growth (µ) was limited by low light (µ = 0.23 d−1), short-term experiments indicated that 0.4 µM NH4+ reduced N2-fixation by ∼90% relative to controls without added NH4+. In fast-growing, high-light-acclimated cultures (µ = 0.68 d−1), 2.0 µM NH4+ was needed to achieve the same effect. In long-term exposures to NO3−, inhibition of N2 fixation also varied with growth rate. In high-light-acclimated, fast-growing cultures, NO3− did not inhibit N2-fixation rates in comparison with cultures growing on N2 alone. Instead NO3− supported even faster growth, indicating that the cellular assimilation rate of N2 alone (i.e. dinitrogen reduction) could not support the light-specific maximum growth rate of Crocosphaera. When growth was severely light-limited, NO3− did not support faster growth rates but instead inhibited N2-fixation rates by 55% relative to controls. These data rest on the basic tenet that light energy is the driver of photoautotrophic growth while various nutrient substrates serve as supports. Our findings provide a novel conceptual framework to examine interactions between N source preferences and predict degrees of inhibition of N2 fixation by fixed N sources based on the growth rate as controlled by light. PMID:25503244

  2. Modulation of the Surface-Layer Protein of Clostridium difficile through Cwp84 Inhibition.

    PubMed

    Gooyit, Major D; Janda, Kim D

    2016-07-01

    Cysteine protease Cwp84 is responsible for surface-layer processing in Clostridium difficile and was also shown to cleave several human extracellular matrix components in vitro. To enable the facile identification and characterization of Cwp84 inhibitors, we developed a fluorogenic 10-mer peptide based on the enzyme's natural substrate SlpA that is amenable for use in FRET-based high-throughput screening. The design of substrate-mimetic inhibitors led to epoxysuccinate 8c, which displayed an inactivation efficiency (kinact/KI) of (4.7 ± 0.3) × 10(4) M(-1) min(-1). Further evaluation of 8c demonstrated its ability to inhibit fibronectin cleavage and, more importantly, subvert surface-layer biogenesis in C. difficile. PMID:27626098

  3. Naringin regulates cholesterol homeostasis and inhibits inflammation via modulating NF-κB and ERK signaling pathways in vitro.

    PubMed

    Liang, Jing; Wang, Changyuan; Peng, Jinyong; Li, Wenshuang; Jin, Yue; Liu, Qi; Meng, Qiang; Liu, Kexin; Sun, Huijun

    2016-02-01

    The main purpose of this study was to examine if naringin contributed to the regulation of cholesterol homeostasis and inflammatory cytokine expressions in cholesterol and 25-OH-cholesterol-treated HepG2 cells and TNF-α-treated HUVECs. The gene and protein expressions related to cholesterol homeostasis and inflammation were determined by quantitative real-time reverse transcription-polymerase chain reaction and Western blotting. We obtained the following results: (1) A concentration-dependent increase of LDLR and CYP7A1 expressions was observed, through activating expressions of SREBP2 and PPARy in HepG2 cells after exposure to naringin; (2) EL gene and protein expressions in HUVECs were inhibited by naringin; (3) the expressions of inflammatory factors such as CRP, TNF-α, ICAM-1 and VCAM-1 in HepG2 cells, ICAM-1 and VCAM-1 in HUVECs restrained by naringin were confirmed; (4) NF-κB and ERK1/2 activities were quenched by naringin. In summary, naringin might not only effectively reduce cholesterol levels by stimulating cholesterol metabolism but also inhibit inflammatory response through reducing inflammatory cytokine expressions. The effects of naringin were achieved via modulating NF-κB and ERK signaling pathways.

  4. Valenced action/inhibition learning in humans is modulated by a genetic variant linked to dopamine D2 receptor expression

    PubMed Central

    Richter, Anni; Guitart-Masip, Marc; Barman, Adriana; Libeau, Catherine; Behnisch, Gusalija; Czerney, Sophia; Schanze, Denny; Assmann, Anne; Klein, Marieke; Düzel, Emrah; Zenker, Martin; Seidenbecher, Constanze I.; Schott, Björn H.

    2014-01-01

    Motivational salience plays an important role in shaping human behavior, but recent studies demonstrate that human performance is not uniformly improved by motivation. Instead, action has been shown to dominate valence in motivated tasks, and it is particularly difficult for humans to learn the inhibition of an action to obtain a reward, but the neural mechanism behind this behavioral specificity is yet unclear. In all mammals, including humans, the monoamine neurotransmitter dopamine is particularly important in the neural manifestation of appetitively motivated behavior, and the human dopamine system is subject to considerable genetic variability. The well-studied TaqIA restriction fragment length polymorphism (rs1800497) has previously been shown to affect striatal dopamine metabolism. In this study we investigated a potential effect of this genetic variation on motivated action/inhibition learning. Two independent cohorts consisting of 87 and 95 healthy participants, respectively, were tested using the previously described valenced go/no-go learning paradigm in which participants learned the reward-associated no-go condition significantly worse than all other conditions. This effect was modulated by the TaqIA polymorphism, with carriers of the A1 allele showing a diminished learning-related performance enhancement in the rewarded no-go condition compared to the A2 homozygotes. This result highlights a modulatory role for genetic variability of the dopaminergic system in individual learning differences of action-valence interaction. PMID:25147510

  5. Equol inhibits proliferation of human gastric carcinoma cells via modulating Akt pathway

    PubMed Central

    Yang, Zhi-Ping; Zhao, Yan; Huang, Fang; Chen, Jie; Yao, Ya-Hong; Li, Jun; Wu, Xiao-Nan

    2015-01-01

    AIM: To investigate the anti-tumor effects of equol in gastric cancer cells and the underlying molecular mechanisms. METHODS: MGC-803 cells were employed for in vitro experiments in this study. Cells were treated with control (vehicle, 0.1% DMSO) or equol under specified dose titration or time courses. Cell viability was examined by MTS assay, and the levels of Ki67 were determined by qPCR and immunofluorescent assay. Changes in cell cycle distribution and apoptosis rate were detected by flow cytometry. The mRNA expression of cyclin E1 and P21WAF1 was determined by qPCR. The protein levels of cell cycle regulators, PARP and Caspase-3 cleavage, and the phosphorylation of Akt were examined by Western blot. In addition, to characterize the role of elevated Akt activation in the anti-tumor effect exerted by equol, Ly294002, a PI3K/AKT pathway inhibitor, was used to pretreat MGC-803 cells. RESULTS: Equol (5, 10, 20, 40, or 80 μmol/L) inhibited viability of MGC-803 cells in a dose- and time-dependent manner after treatment for 24, 36, or 48 h (P < 0.05 for all). Equol also decreased the mRNA (P < 0.05 for 12 and 24 h treatment) and protein levels of Ki67. Equol treatment significantly induced G0/G1 cell cycle arrest (P < 0.05), with the percentages of G0/G1 cells of 32.23% ± 3.62%, 36.31% ± 0.24%, 45.58% ± 2.29%, and 65.10% ± 2.04% for equol (0, 10, 20, or 30 μmol/L) treatment, respectively, accompanied by a significant decrease of CDK2/4 (P < 0.05 for 24 and 48 h treatment) and Cyclin D1/Cyclin E1 (P < 0.05), and an increased level of P21WAF1 (P < 0.05). A marked increase of apoptosis was observed, with the percentages of apoptotic cells of 5.01% ± 0.91%, 14.57% ± 0.99%, 37.40% ± 0.58%, and 38.46% ± 2.01% for equol (0, 5, 10, or 20 μmol/L) treatment, respectively, accompanied by increased levels of cleaved PARP and caspase-3. In addition, we found that equol treatment increased P-Akt (Ser473 and Thr308) at 12 and 24 h compared to vehicle-treated control

  6. Modulation of Compartmentalised Cyclic Nucleotide Signalling via Local Inhibition of Phosphodiesterase Activity

    PubMed Central

    Brescia, Marcella; Zaccolo, Manuela

    2016-01-01

    Cyclic nucleotide phosphodiesterases (PDEs) are the only enzymes that degrade the cyclic nucleotides cAMP and cGMP, and play a key role in modulating the amplitude and duration of the signal delivered by these two key intracellular second messengers. Defects in cyclic nucleotide signalling are known to be involved in several pathologies. As a consequence, PDEs have long been recognized as potential drug targets, and they have been the focus of intense research for the development of therapeutic agents. A number of PDE inhibitors are currently available for the treatment of disease, including obstructive pulmonary disease, erectile dysfunction, and heart failure. However, the performance of these drugs is not always satisfactory, due to a lack of PDE-isoform specificity and their consequent adverse side effects. Recent advances in our understanding of compartmentalised cyclic nucleotide signalling and the role of PDEs in local regulation of cAMP and cGMP signals offers the opportunity for the development of novel strategies for therapeutic intervention that may overcome the current limitation of conventional PDE inhibitors. PMID:27706091

  7. Bromelain Inhibits Allergic Sensitization and Murine Asthma via Modulation of Dendritic Cells.

    PubMed

    Secor, Eric R; Szczepanek, Steven M; Castater, Christine A; Adami, Alexander J; Matson, Adam P; Rafti, Ektor T; Guernsey, Linda; Natarajan, Prabitha; McNamara, Jeffrey T; Schramm, Craig M; Thrall, Roger S; Silbart, Lawrence K

    2013-01-01

    The incidence of atopic conditions has increased in industrialized countries. Persisting symptoms and concern for drug side-effects lead patients toward adjunctive treatments such as phytotherapy. Previously, we have shown that Bromelain (sBr), a mixture of cysteine proteases from pineapple, Ananas comosus, inhibits ovalbumin (OVA)-induced murine model of allergic airway disease (AAD). However, sBr's effect on development of AAD when treatment is administered throughout OVA-alum sensitization was unknown and is the aim of the present study. C57BL/6J mice were sensitized with OVA/alum and challenged with 7 days OVA aerosol. sBr 6 mg/kg/0.5 ml or PBS vehicle were administered throughout sensitization. Lung, bronchoalveolar lavage (BAL), spleen, and lymph nodes were processed for flow cytometry and OVA-specific IgE was determined via ELISA. sBr treatment throughout OVA-alum sensitization significantly reduced the development of AAD (BAL eosinophils and lymphocytes). OVA-specific IgE and OVA TET(+) cells were decreased. sBr reduced CD11c(+) dendritic cell subsets, and in vitro treatment of DCs significantly reduced CD44, a key receptor in both cell trafficking and activation. sBr was shown to reduce allergic sensitization and the generation of AAD upon antigen challenge. These results provide additional insight into sBr's anti-inflammatory and antiallergic properties and rationale for translation into the clinical arena.

  8. Cigarette Smoke Component Acrolein Modulates Chromatin Assembly by Inhibiting Histone Acetylation*

    PubMed Central

    Chen, Danqi; Fang, Lei; Li, Hongjie; Tang, Moon-shong; Jin, Chunyuan

    2013-01-01

    Chromatin structure and gene expression are both regulated by nucleosome assembly. How environmental factors influence histone nuclear import and the nucleosome assembly pathway, leading to changes in chromatin organization and transcription, remains unknown. Acrolein (Acr) is an α,β-unsaturated aldehyde, which is abundant in the environment, especially in cigarette smoke. It has recently been implicated as a potential major carcinogen of smoking-related lung cancer. Here we show that Acr forms adducts with histone proteins in vitro and in vivo and preferentially reacts with free histones rather than with nucleosomal histones. Cellular fractionation analyses reveal that Acr exposure specifically inhibits acetylations of N-terminal tails of cytosolic histones H3 and H4, modifications that are important for nuclear import and chromatin assembly. Notably, Acr exposure compromises the delivery of histone H3 into chromatin and increases chromatin accessibility. Moreover, changes in nucleosome occupancy at several genomic loci are correlated with transcriptional responses to Acr exposure. Our data provide new insights into mechanisms whereby environmental factors interact with the genome and influence genome function. PMID:23770671

  9. Enterostatin inhibition of dietary fat intake is modulated through the melanocortin system.

    PubMed Central

    Lin, Ling; Park, MieJung; York, David A.

    2007-01-01

    Enterostatin injected into the amygdala selectively reduces dietary fat intake by an action that involves a serotonergic component in the paraventricular nucleus. We have investigated the role of melanocortin signaling in the response to enterostatin by studies in melanocortin 4 receptor (MC4R) knockout mice and by the use of the MC4R and MC3R antagonist SHU9119, and by neurochemical phenotyping of enterostatin activated cells. We also determined the effect of enterostatin in vivo on the expression of AgRP in the hypothalamus and amygdala of rats and in culture on a GT1-7 neuronal cell line. Enterostatin had no effect on food intake in MC4R knock out mice. SHU9119 icv blocked the feeding response to amygdala enterostatin in rats. Amygdala enterostatin induced fos activation in α-melanocyte stimulating hormone (α-MSH) neurons in the arcuate nucleus. Enterostatin also reduced the expression of AgRP in the hypothalamus and amygdala and in GT1-7 cells. These data suggest enterostatin inhibits dietary fat intake through a melanocortin signaling pathway. PMID:17113194

  10. Cigarette smoke component acrolein modulates chromatin assembly by inhibiting histone acetylation.

    PubMed

    Chen, Danqi; Fang, Lei; Li, Hongjie; Tang, Moon-shong; Jin, Chunyuan

    2013-07-26

    Chromatin structure and gene expression are both regulated by nucleosome assembly. How environmental factors influence histone nuclear import and the nucleosome assembly pathway, leading to changes in chromatin organization and transcription, remains unknown. Acrolein (Acr) is an α,β-unsaturated aldehyde, which is abundant in the environment, especially in cigarette smoke. It has recently been implicated as a potential major carcinogen of smoking-related lung cancer. Here we show that Acr forms adducts with histone proteins in vitro and in vivo and preferentially reacts with free histones rather than with nucleosomal histones. Cellular fractionation analyses reveal that Acr exposure specifically inhibits acetylations of N-terminal tails of cytosolic histones H3 and H4, modifications that are important for nuclear import and chromatin assembly. Notably, Acr exposure compromises the delivery of histone H3 into chromatin and increases chromatin accessibility. Moreover, changes in nucleosome occupancy at several genomic loci are correlated with transcriptional responses to Acr exposure. Our data provide new insights into mechanisms whereby environmental factors interact with the genome and influence genome function.

  11. Antioxidant modulation of skin inflammation: preventing inflammatory progression by inhibiting neutrophil influx

    PubMed Central

    McGilvray, Ian D.; Rotstein, Ori D.

    1999-01-01

    Objective To test the hypothesis that antioxidants might affect local inflammation by impairing inflammatory cell influx. Design A laboratory study using a Swiss–Webster mouse model of local inflammation. Setting A university-affiliated hospital. Methods Intradermal injection of 30 μg of S. minnesota endotoxin (LPS) to Swiss–Webster mice initiates a local inflammatory reaction characterized by an early rise in vascular permeability and a later influx of neutrophils. Animals were pretreated intraperitoneally with either pyrrolidine dithiocarbamate (PDTC, 2 mmol/kg), which inhibits free radical generation, or dimethylthiourea (DMTU, 450 mg/kg), a free radical scavenger. Main outcome measures Histologic findings of tissue samples taken at sites of injection; local changes in tissue vascular permeability (PI) determined by iodine-125 albumin injection before sacrifice; neutrophil accumulation quantified by tissue myeloperoxidase levels; tissue levels of the endothelial adhesion molecules intercellular adhesion molecule-1 protein (ICAM-1) and vascular cell adhesion molecule-1 protein (VCAM-1) assessed by immunohistochemistry and Western blot, respectively. Results Neither antioxidant had a significant effect on the early increase in PI, but both decreased the late rise in PI and reduced neutrophil influx. Both ICAM-1 and VCAM-1 were upregulated in response to LPS; however, only the increase in VCAM-1 was attenuated by antioxidant pretreatment. Conclusion These data suggest that antioxidants disrupt the propagation phase of an inflammatory response, possibly by altering neutrophil migration. PMID:10223071

  12. Modulation of attentional inhibition by norepinephrine and cortisol after psychological stress.

    PubMed

    Skosnik, P D; Chatterton, R T; Swisher, T; Park, S

    2000-04-01

    Two of the most salient physiological responses to stress are increased norepinephrine (NE) and cortisol (CORT) activities. However, it is unclear how these neurochemical events affect cognition, especially attention. We examined the effects of mild psychological stress on selective attention, as assessed by the negative priming (NP) paradigm. Salivary measures of the stress hormone CORT and alpha-amylase (a correlate of NE) were assayed to probe the relationship between the stress response and attentional inhibition. Healthy subjects (N = 20) engaged in the attention task, which was then followed by 15 min of a stressful video game before a return to the attentional task. Baseline saliva samples were obtained before the experiment began, 1 min after the video-game stressor, and 20 min post-stress. Subjects showed a significant reduction in NP and a decrease in reaction time (RT) after the video game. Moreover, alpha-amylase levels increased significantly after the stressor, indicating the role of NE in the acute stress response. While CORT levels remained unchanged after stress, CORT correlated significantly with both NP scores and RT after the stressor. These results imply that mild psychological stress can significantly alter attentional processes. Given the increase in alpha-amylase and the correlation between attention and CORT after stress, it seems likely that attentional processes are under tight control by brain systems which mediate the fight-or-flight response.

  13. Acacia ferruginea inhibits cyclophosphamide-induced immunosuppression and urotoxicity by modulating cytokines in mice.

    PubMed

    Sakthivel, K M; Guruvayoorappan, Chandrasekaran

    2015-01-01

    Cyclophosphamide (CTX), commonly used as an anti-neoplastic drug, can cause adverse side-effects including immunotoxicity and urotoxicity. Increasingly, plants have become sources of therapeutics that can help to restore host immunity to normal. In this study, Acacia ferruginea was assessed for an ability to protect mice against/mitigate CTX-induced toxicity. Co-administration of an extract of A. ferruginea (10 mg/kg BW, IP daily) for 10 consecutive days reduced CTX (25 mg/kg BW, IP daily)-induced toxicity. Apart from improvements in bladder and small intestine morphology, there was marked improvement in anti-oxidant (glutathione) levels in the bladder, suggesting a role for the anti-oxidant in reducing CTX-induced urotoxicity. Moreover, use of the extract significantly increased total leukocyte counts and bone marrow cellularity/α-esterase activity in CTX-treated mice which suggested a protective effect on the hematopoietic system. Co-treatment with the extract also prevented decreases in organ (liver, kidney, spleen, thymus) weight as well as body weight, thereby seemingly lessening the potential impact of CTX on the host immune system. Further, CTX-induced increases in serum aspartate transanimase, alanine transaminase, and alkaline phosphatase were reversed by extract co-treatment, as were alterations in in situ formation/release of interferon (IFN)-γ, interleukin (IL)-2, granulocyte-macrophage colony stimulating factor (GM-CSF), and tumor necrosis factor (TNF)-α. Overall, this study indicated there were some protective effects from use of an extract of A. ferruginea against CTX-induced toxicities, in part through modulation of levels of anti-oxidants and pro-inflammatory cytokines.

  14. Inhibition of Hsp27 Radiosensitizes Head-and-Neck Cancer by Modulating Deoxyribonucleic Acid Repair

    SciTech Connect

    Guttmann, David M.; Hart, Lori; Du, Kevin; Seletsky, Andrew; Koumenis, Constantinos

    2013-09-01

    Purpose: To present a novel method of tumor radiosensitization through Hsp27 knockdown using locked nucleic acid (LNA) and to investigate the role of Hsp27 in DNA double strand break (DSB) repair. Methods and Materials: Clonogenic survival assays, immunoblotting, the proximity ligation assay, and γH2AX foci analysis were conducted in SQ20B and FaDu human head-and-neck cancer cell lines treated with Hsp27 LNA and Hsp27 short hairpin RNA (shRNA). Additionally, nude mice with FaDu flank tumors were treated with fractionated radiation therapy after pretreatment with Hsp27 LNA and monitored for tumor growth. Results: Hsp27 LNA and Hsp27 shRNA radiosensitized head-and-neck cancer cell lines in an Hsp27-dependent manner. Ataxia-Telangectasia Mutated-mediated DNA repair signaling was impaired in irradiated cells with Hsp27 knockdown. ATM kinase inhibition abrogated the radiosensitizing effect of Hsp27. Furthermore, Hsp27 LNA and shRNA both attenuated DNA repair kinetics after radiation, and Hsp27 was found to colocalize with ATM in both untreated and irradiated cells. Last, combined radiation and Hsp27 LNA treatment in tumor xenografts in nude mice suppressed tumor growth compared with either treatment alone. Conclusions: These results support a radiosensitizing property of Hsp27 LNA in vitro and in vivo, implicate Hsp27 in double strand break repair, and suggest that Hsp27 LNA might eventually serve as an effective clinical agent in the radiotherapy of head-and-neck cancer.

  15. Dietary phenolic compounds selectively inhibit the individual subunits of maltase-glucoamylase and sucrase-isomaltase with the potential of modulating glucose release

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, it was hypothesized that dietary phenolic compounds selectively inhibit the individual C- and N-terminal (Ct, Nt) subunits of the two small intestinal alpha-glucosidases, maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI), for a modulated glycemic carbohydrate digestion. The inhi...

  16. Inhibition of microRNA-155 sensitizes lung cancer cells to irradiation via suppression of HK2-modulated glucose metabolism.

    PubMed

    Lv, Xin; Yao, Li; Zhang, Jianli; Han, Ping; Li, Cuiyun

    2016-08-01

    MicroRNAs (miRNAs) are small non-coding regulatory RNAs, which are involved in the post-transcriptional regulation of gene expression. miRNA (miR)-155, which has previously been reported to be overexpressed in lung cancer, is correlated with poor patient prognosis. The present study aimed to investigate the effects of miR‑155 on the radiosensitivity of human non‑small cell lung cancer (NSCLC) cells. To explore the roles of miRNAs in the regulation of irradiation sensitivity of human lung cancer cells, the expressions of miR‑155 in response to irradiation, have been studied by RT‑qPCR, and the putative direct target of miR‑155 was identified by western blot and luciferase assays. The results of the present study revealed that the expression of miR‑155 was induced by irradiation, thus suggesting a positive correlation between miR‑155 and radiosensitivity. Furthermore, overexpression of miR‑155 rendered lung cancer cells resistant to irradiation. In addition, hexokinase 2 (HK2) was identified as an indirect target of miR‑155; exogenous overexpression of miR‑155 upregulated the expression of HK2, whereas inhibition of miR‑155 by antisense miRNA suppressed HK2 expression. In addition, HK2‑modulated glucose metabolism was significantly upregulated by overexpression of miR‑155. Notably, inhibition of miR‑155 sensitized lung cancer cells to irradiation via suppression of glucose metabolism. In conclusion, the present study reported a novel function for miR‑155 in the regulation of NSCLC cell radiosensitivity, thus suggesting that miR‑155 may be considered a therapeutic target for the development of anticancer drugs. PMID:27315591

  17. Environmental CO2 inhibits Caenorhabditis elegans egg-laying by modulating olfactory neurons and evokes widespread changes in neural activity

    PubMed Central

    Fenk, Lorenz A.; de Bono, Mario

    2015-01-01

    Carbon dioxide (CO2) gradients are ubiquitous and provide animals with information about their environment, such as the potential presence of prey or predators. The nematode Caenorhabditis elegans avoids elevated CO2, and previous work identified three neuron pairs called “BAG,” “AFD,” and “ASE” that respond to CO2 stimuli. Using in vivo Ca2+ imaging and behavioral analysis, we show that C. elegans can detect CO2 independently of these sensory pathways. Many of the C. elegans sensory neurons we examined, including the AWC olfactory neurons, the ASJ and ASK gustatory neurons, and the ASH and ADL nociceptors, respond to a rise in CO2 with a rise in Ca2+. In contrast, glial sheath cells harboring the sensory endings of C. elegans’ major chemosensory neurons exhibit strong and sustained decreases in Ca2+ in response to high CO2. Some of these CO2 responses appear to be cell intrinsic. Worms therefore may couple detection of CO2 to that of other cues at the earliest stages of sensory processing. We show that C. elegans persistently suppresses oviposition at high CO2. Hermaphrodite-specific neurons (HSNs), the executive neurons driving egg-laying, are tonically inhibited when CO2 is elevated. CO2 modulates the egg-laying system partly through the AWC olfactory neurons: High CO2 tonically activates AWC by a cGMP-dependent mechanism, and AWC output inhibits the HSNs. Our work shows that CO2 is a more complex sensory cue for C. elegans than previously thought, both in terms of behavior and neural circuitry. PMID:26100886

  18. Phosphatase-1 and -2A inhibition modulates apoptosis in human osteoarthritis chondrocytes independently of nitric oxide production

    PubMed Central

    Lopez-Armada, M; Carames, B; Cillero-Pastor, B; Lires-Dean, M; Maneiro, E; Fuentes, I; Ruiz, C; Galdo, F; Blanco, F

    2005-01-01

    Methods: Human OA chondrocytes were isolated from cartilage obtained from the femoral heads of patients undergoing joint replacement surgery. Cell viability was evaluated by MTT assay. Apoptosis was quantified by ELISA, which measures DNA fragmentation. Nitric oxide (NO) production was evaluated by the Greiss method, and inducible nitric oxide synthase (iNOS) protein synthesis was studied by western blotting. Results: Inhibition of PP1/2A by the specific inhibitor okadaic acid (OKA) dose and time dependently caused a reduction of cell viability (OKA at 50 nmol/l: a reduction to 60% and 43% at 48 and 72 hours, respectively). Genomic DNA from chondrocytes treated with OKA at 50 and 100 nmol/l for 48 hours displayed increased internucleosomal DNA fragmentation by 11 and 13 fields, respectively. Light microscopy and DAPI studies showed that OKA induced DNA condensation and fragmentation, typical of death by apoptosis. The caspase inhibitors Z-VAD-FMK and Z-DEVD-FMK increased cell viability, reduced by OKA at 50 nmol/l to 87% and 73%, respectively. OKA did not increase iNOS protein synthesis or NO production. Conclusion: PP1/2A modulate apoptosis in human OA chondrocytes; this is independent of NO production but dependent on caspases. PMID:15958763

  19. Muscarinic Acetylcholine Receptor M3 Modulates Odorant Receptor Activity via Inhibition of β-Arrestin-2 Recruitment

    PubMed Central

    Jiang, Yue; Li, Yun Rose; Tian, Huikai; Ma, Minghong; Matsunami, Hiroaki

    2015-01-01

    The olfactory system in rodents serves a critical function in social, reproductive, and survival behaviors. Processing of chemosensory signals in the brain is dynamically regulated in part by an animal's physiological state. We previously reported that type 3 muscarinic acetylcholine receptors (M3-Rs) physically interact with odorant receptors (ORs) to promote odor-induced responses in a heterologous expression system. However, it is not known how M3-Rs affect the ability of olfactory sensory neurons (OSNs) to respond to odors. Here, we show that an M3-R antagonist attenuates odor-induced responses in OSNs from wild-type, but not M3-R-null mice. Using a novel molecular assay, we demonstrate that the activation of M3-Rs inhibits the recruitment of β-arrestin-2 to ORs, resulting in a potentiation of odor-induced response in OSNs. These results suggest a role for acetylcholine in modulating olfactory processing at the initial stages of signal transduction in the olfactory system. PMID:25800153

  20. Inhibition of growth of established human glioma cell lines by modulators of the protein kinase-C system

    SciTech Connect

    Couldwell, W.T.; Antel, J.P.; Apuzzo, M.L.; Yong, V.W. )

    1990-10-01

    The protein kinase-C (PKC) second messenger system contributes to regulation of cell growth and differentiation. This study was undertaken to examine the effects of modulators of the PKC enzyme system on the state of differentiation and proliferation rates of human gliomas in vitro. The administration of the PKC-activating phorbol esters 4-beta-phorbol-12,13-dibutyrate (PDB) and phorbol-12-myristate-13-acetate (PMA) resulted in a dose-related inhibition of growth of human glioma cell lines in vitro as measured by 3H-thymidine uptake. The synthetic nonphorbol PKC activator (SC-9) produced an even more pronounced decrease of 3H-thymidine uptake. Diacylglycerol, an endogenous activator of the system, applied externally, transiently decreased the proliferation, in concordance with its short-lived existence in vivo. Conversely, the administration of 4-alpha-phorbol-12,13-didecanoate (alpha-PDD), a phorbol ester that binds but does not activate the enzyme, had no effect on the proliferation rate. At the dosages that maximally decreased proliferation, there was no evidence of direct glioma cell lysis induced by these agents as measured by a chromium-release assay. Immunocytochemical analysis and cytofluorometric measurement of glial fibrillary acidic protein (GFAP) staining in the treated cultures revealed an increase in GFAP staining over control cultures. In contrast to the response of glioma cells, nonmalignant human adult astrocytes treated with the PKC activators responded by increasing their proliferation rate. The authors postulate that the diametrically opposed effects of PKC activators on nonmalignant astrocytes versus glioma growth may be due to a high intrinsic PKC activity in glioma cells, with resultant down-regulation of enzyme activity following the administration of the pharmacological activators.

  1. Modulation of antioxidant defense by Alpinia galanga and Curcuma aromatica extracts correlates with their inhibition of UVA-induced melanogenesis.

    PubMed

    Panich, Uraiwan; Kongtaphan, Kamolratana; Onkoksoong, Tassanee; Jaemsak, Kannika; Phadungrakwittaya, Rattana; Thaworn, Athiwat; Akarasereenont, Pravit; Wongkajornsilp, Adisak

    2010-04-01

    Ultraviolet A (UVA) irradiation is suggested to contribute to melanogenesis through promoting cellular oxidative stress and impairing antioxidant defenses. An overproduction of melanin can be associated with melanoma skin cancer and hyperpigmentation. Therefore, developing effective antimelanogenic agents is of importance. Alpinia galanga (AG) and Curcuma aromatica (CA) are traditional medicinal plants widely used for skin problems. Hence, this study investigated the antimelanogenic effects of AG and CA extracts (3.8-30 microg/ml) by assessing tyrosinase activity, tyrosinase mRNA levels, and melanin content in human melanoma cells (G361) exposed to UVA. The roles in protecting against melanogenesis were examined by evaluating their inhibitory effects on UVA-induced cellular oxidative stress and modulation of antioxidant defenses including antioxidant enzymes, catalase (CAT) and glutathione peroxidase (GPx), and intracellular glutathione (GSH). In addition, possible active compounds accountable for biological activities of the extracts were identified by thin layer chromatography (TLC)-densitometric analysis. Our study demonstrated that UVA (8 J/cm(2)) induced both tyrosinase activity and mRNA levels and UVA (16 J/cm(2))-mediated melanin production were suppressed by the AG or CA extracts at noncytotoxic concentrations. Both extracts were able to protect against UVA-induced cellular oxidant formation and depletion of CAT and GPx activities and GSH content in a dose-dependent manner. Moreover, TLC-densitometric analysis detected the presence of eugenol and curcuminoids in AG and CA, respectively. This is the first report representing promising findings on AG and CA extract-derived antityrosinase properties correlated with their antioxidant potential. Inhibiting cellular oxidative stress and improving antioxidant defenses might be the mechanisms by which the extracts yield the protective effects on UVA-dependent melanogenesis.

  2. Hydroxybenzothiophene Ketones Are Efficient Pre-mRNA Splicing Modulators Due to Dual Inhibition of Dyrk1A and Clk1/4.

    PubMed

    Schmitt, Christian; Miralinaghi, Parisa; Mariano, Marica; Hartmann, Rolf W; Engel, Matthias

    2014-09-11

    Dysregulated usage of pre-mRNA splicing sites contributes to the progression of cancer, neurodegenerative diseases, and viral infections. Serine/arginine-rich (SR) proteins play major roles in the splice site recognition and are largely regulated by phosphorylation. This provides an option for the pharmacological correction of aberrant splicing by inhibiting the relevant kinases. Cdc2-like kinases (Clks) and dual specificity tyrosine phosphorylation-regulated kinases (Dyrks) were both reported to phosphorylate numerous SR proteins in vitro and in vivo. In this study, we describe the discovery of new selective dual Clk/Dyrk1A/1B inhibitors, which are able to modulate alternative pre-mRNA splicing of model gene transcripts in cells with submicromolar potencies. The optimization process yielded a dual Clk and Dyrk inhibitor with exceptionally high ligand efficiency. Our results suggested that dual inhibition of both Clk1 and Dyrk1A increased the efficacy of pre-mRNA splicing modulation. PMID:25221649

  3. Pre-Synaptic Inhibition of Afferent Feedback in the Macaque Spinal Cord Does Not Modulate with Cycles of Peripheral Oscillations Around 10 Hz

    PubMed Central

    Galán, Ferran; Baker, Stuart N.

    2015-01-01

    Spinal interneurons are partially phase-locked to physiological tremor around 10 Hz. The phase of spinal interneuron activity is approximately opposite to descending drive to motoneurons, leading to partial phase cancellation and tremor reduction. Pre-synaptic inhibition of afferent feedback modulates during voluntary movements, but it is not known whether it tracks more rapid fluctuations in motor output such as during tremor. In this study, dorsal root potentials (DRPs) were recorded from the C8 and T1 roots in two macaque monkeys following intra-spinal micro-stimulation (random inter-stimulus interval 1.5–2.5 s, 30–100 μA), whilst the animals performed an index finger flexion task which elicited peripheral oscillations around 10 Hz. Forty one responses were identified with latency < 5 ms; these were narrow (mean width 0.59 ms), and likely resulted from antidromic activation of afferents following stimulation near terminals. Significant modulation during task performance occurred in 16/41 responses, reflecting terminal excitability changes generated by pre-synaptic inhibition (Wall's excitability test). Stimuli falling during large-amplitude 8–12 Hz oscillations in finger acceleration were extracted, and sub-averages of DRPs constructed for stimuli delivered at different oscillation phases. Although some apparent phase-dependent modulation was seen, this was not above the level expected by chance. We conclude that, although terminal excitability reflecting pre-synaptic inhibition of afferents modulates over the timescale of a voluntary movement, it does not follow more rapid changes in motor output. This suggests that pre-synaptic inhibition is not part of the spinal systems for tremor reduction described previously, and that it plays a role in overall—but not moment-by-moment—regulation of feedback gain. PMID:26635536

  4. Selective inhibition of prostaglandin E2 receptors EP2 and EP4 modulates DNA methylation and histone modification machinery proteins in human endometriotic cells.

    PubMed

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

    2015-07-01

    Endometriosis is an inflammatory gynecological disease of reproductive-age women. The prevalence of endometriosis is 5-10% in reproductive-age women. Modern medical treatments are directed to inhibit the action of estrogen in endometriotic cells. However, hormonal therapies targeting estrogen can be prescribed only for a short time because of their undesirable side effects. Recent studies from our laboratory, using human endometriotic epithelial cell line 12Z and stromal cell line 22B derived from red lesion, discovered that selective inhibition of prostaglandin E2 (PGE2) receptors EP2 and EP4 inhibits adhesion, invasion, growth, and survival of 12Z and 22B cells by modulating integrins, MMPs and TIMPs, cell cycle, survival, and intrinsic apoptotic pathways, suggesting multiple epigenetic mechanisms. The novel findings of the present study indicate that selective pharmacological inhibition of EP2 and EP4: (i) decreases expression of DNMT3a, DNMT3b, H3K9me3, H3K27me3, SUV39H1, HP1a, H3K27, EZH2, JMJD2a, HDAC1, HDAC3, MeCP2, CoREST and Sin3A; (ii) increases expression of H3K4me3, H3H9ac, H3K27ac; and (iii) does not modulate the expression of DNMT1, hSET1, LSD1, MBD1, p300, HDAC2, and JMJD3 epigenetic machinery proteins in an epithelial and stromal cell specific manner. In this study, we report for the first time that inhibition of PGE2-EP2/EP4 signaling modulates DNA methylation, H3 histone methylation and acetylation, and epigenetic memory machinery proteins in human endometriotic epithelial cells and stromal cells. Thus, targeting EP2 and EP4 receptors may emerge as long-term nonsteroidal therapy for treatment of active endometriotic lesions in women.

  5. Paris saponin II inhibits human ovarian cancer cell-induced angiogenesis by modulating NF-κB signaling.

    PubMed

    Yang, Mei; Zou, Juan; Zhu, Hongmei; Liu, Shanling; Wang, He; Bai, Peng; Xiao, Xue

    2015-05-01

    The clinical applications of Rhizoma paridis in traditional Chinese medicine are well known. However, the therapeutic potential of Rhizoma paridis and its active component such as Paris saponin I (polyphyllin D) and Paris saponin II (PSII) (formosanin C) in cancer treatments have not yet been fully explored. Recent studies have demonstrated that PSII and chemoagents exhibit comparable inhibitory affects against human ovarian cancer cell growth. Since NF-κB, a ubiquitous transcription factor that plays an important role in cancer biology, is often associated with gynecological cancers, in the present study, we evaluated the possibility that PSII modulates NF-κB activity and VEGF-mediated angiogenesis and elucidated the molecular mechanisms underlying such effects. We assessed the effects of PSII on NF-κB activity in SKOV3 tumor cells and on tumor cell induced-angiogenesis using standardized angiogenesis in vitro, ex vivo and in vivo assays, western blot analysis and kinase assay. We also assessed the effect of the super-engineered repressor of IĸBα and its effect, in combination with PSII treatment on tumor growth and angiogenesis in xenograft athymic mouse models of ovarian cancer (SKOV3 and SKOV3/mutant IĸBα cells) using color Doppler ultrasound and traditional immunohistochemistry. We showed that PSII suppressed NF-κB activation as a result of the reduction in IKKβ kinase activity on its substrate IκBα and the expression of IKKβ. Compromising NF-κB activation reduced the expression of NF-κB-downstream targets such as VEGF, Bcl-2 and Bcl-xL. Such inhibitory effects at molecular levels appear to compromise tumor growth and angiogenesis. Most importantly, the combination of PSII treatment and constitutive repression of IĸBα activity exhibited marked inhibitory effects against human ovarian cancer cell growth in a xenograft mouse model of ovarian cancer. For the first time, we provide evidence showing that PSII potently inhibits angiogenesis

  6. EGFR inhibition in glioma cells modulates Rho signaling to inhibit cell motility and invasion and cooperates with temozolomide to reduce cell growth.

    PubMed

    Ramis, Guillem; Thomàs-Moyà, Elena; Fernández de Mattos, Silvia; Rodríguez, José; Villalonga, Priam

    2012-01-01

    Enforced EGFR activation upon gene amplification and/or mutation is a common hallmark of malignant glioma. Small molecule EGFR tyrosine kinase inhibitors, such as erlotinib (Tarceva), have shown some activity in a subset of glioma patients in recent trials, although the reported data on the cellular basis of glioma cell responsiveness to these compounds have been contradictory. Here we have used a panel of human glioma cell lines, including cells with amplified or mutant EGFR, to further characterize the cellular effects of EGFR inhibition with erlotinib. Dose-response and cellular growth assays indicate that erlotinib reduces cell proliferation in all tested cell lines without inducing cytotoxic effects. Flow cytometric analyses confirm that EGFR inhibition does not induce apoptosis in glioma cells, leading to cell cycle arrest in G(1). Interestingly, erlotinib also prevents spontaneous multicellular tumour spheroid growth in U87MG cells and cooperates with sub-optimal doses of temozolomide (TMZ) to reduce multicellular tumour spheroid growth. This cooperation appears to be schedule-dependent, since pre-treatment with erlotinib protects against TMZ-induced cytotoxicity whereas concomitant treatment results in a cooperative effect. Cell cycle arrest in erlotinib-treated cells is associated with an inhibition of ERK and Akt signaling, resulting in cyclin D1 downregulation, an increase in p27(kip1) levels and pRB hypophosphorylation. Interestingly, EGFR inhibition also perturbs Rho GTPase signaling and cellular morphology, leading to Rho/ROCK-dependent formation of actin stress fibres and the inhibition of glioma cell motility and invasion.

  7. GABAA receptor-mediated feedforward and feedback inhibition differentially modulate the gain and the neural code transformation in hippocampal CA1 pyramidal cells.

    PubMed

    Jang, Hyun Jae; Park, Kyerl; Lee, Jaedong; Kim, Hyuncheol; Han, Kyu Hun; Kwag, Jeehyun

    2015-12-01

    Diverse variety of hippocampal interneurons exists in the CA1 area, which provides either feedforward (FF) or feedback (FB) inhibition to CA1 pyramidal cell (PC). However, how the two different inhibitory network architectures modulate the computational mode of CA1 PC is unknown. By investigating the CA3 PC rate-driven input-output function of CA1 PC using in vitro electrophysiology, in vitro-simulation of inhibitory network, and in silico computational modeling, we demonstrated for the first time that GABAA receptor-mediated FF and FB inhibition differentially modulate the gain, the spike precision, the neural code transformation and the information capacity of CA1 PC. Recruitment of FF inhibition buffered the CA1 PC spikes to theta-frequency regardless of the input frequency, abolishing the gain and making CA1 PC insensitive to its inputs. Instead, temporal variability of the CA1 PC spikes was increased, promoting the rate-to-temporal code transformation to enhance the information capacity of CA1 PC. In contrast, the recruitment of FB inhibition sub-linearly transformed the input rate to spike output rate with high gain and low spike temporal variability, promoting the rate-to-rate code transformation. These results suggest that GABAA receptor-mediated FF and FB inhibitory circuits could serve as network mechanisms for differentially modulating the gain of CA1 PC, allowing CA1 PC to switch between different computational modes using rate and temporal codes ad hoc. Such switch will allow CA1 PC to efficiently respond to spatio-temporally dynamic inputs and expand its computational capacity during different behavioral and neuromodulatory states in vivo.

  8. Myelin-mediated inhibition of oligodendrocyte precursor differentiation can be overcome by pharmacological modulation of Fyn-RhoA and protein kinase C signalling

    PubMed Central

    Baer, Alexandra S.; Syed, Yasir A.; Kang, Sung Ung; Mitteregger, Dieter; Vig, Raluca; ffrench-Constant, Charles; Franklin, Robin J. M.; Altmann, Friedrich; Lubec, Gert

    2009-01-01

    Failure of oligodendrocyte precursor cell (OPC) differentiation contributes significantly to failed myelin sheath regeneration (remyelination) in chronic demyelinating diseases. Although the reasons for this failure are not completely understood, several lines of evidence point to factors present following demyelination that specifically inhibit differentiation of cells capable of generating remyelinating oligodendrocytes. We have previously demonstrated that myelin debris generated by demyelination inhibits remyelination by inhibiting OPC differentiation and that the inhibitory effects are associated with myelin proteins. In the present study, we narrow down the spectrum of potential protein candidates by proteomic analysis of inhibitory protein fractions prepared by CM and HighQ column chromatography followed by BN/SDS/SDS–PAGE gel separation using Nano-HPLC-ESI-Q-TOF mass spectrometry. We show that the inhibitory effects on OPC differentiation mediated by myelin are regulated by Fyn-RhoA-ROCK signalling as well as by modulation of protein kinase C (PKC) signalling. We demonstrate that pharmacological or siRNA-mediated inhibition of RhoA-ROCK-II and/or PKC signalling can induce OPC differentiation in the presence of myelin. Our results, which provide a mechanistic link between myelin, a mediator of OPC differentiation inhibition associated with demyelinating pathologies and specific signalling pathways amenable to pharmacological manipulation, are therefore of significant potential value for future strategies aimed at enhancing CNS remyelination. PMID:19208690

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

    ERIC Educational Resources Information Center

    Schmidt, Loren J.; Strowbridge, Ben W.

    2014-01-01

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

  10. Modulation of PI3K-LXRα-dependent lipogenesis mediated by oxidative/nitrosative stress contributes to inhibition of HCV replication by quercetin.

    PubMed

    Pisonero-Vaquero, Sandra; García-Mediavilla, María V; Jorquera, Francisco; Majano, Pedro L; Benet, Marta; Jover, Ramiro; González-Gallego, Javier; Sánchez-Campos, Sonia

    2014-03-01

    There is experimental evidence that some antioxidant flavonoids show therapeutic potential in the treatment of hepatitis C through inhibition of hepatitis C virus (HCV) replication. We examined the effect of treatment with the flavonols quercetin and kaempferol, the flavanone taxifolin and the flavone apigenin on HCV replication efficiency in an in vitro model. While all flavonoids studied were able to reduce viral replication at very low concentrations (ranging from 0.1 to 5 μM), quercetin appeared to be the most effective inhibitor of HCV replication, showing a marked anti-HCV activity in replicon-containing cells when combined with interferon (IFN)α. The contribution of oxidative/nitrosative stress and lipogenesis modulation to inhibition of HCV replication by quercetin was also examined. As expected, quercetin decreased HCV-induced reactive oxygen and nitrogen species (ROS/RNS) generation and lipoperoxidation in replicating cells. Quercetin also inhibited liver X receptor (LXR)α-induced lipid accumulation in LXRα-overexpressing and replicon-containing Huh7 cells. The mechanism underlying the LXRα-dependent lipogenesis modulatory effect of quercetin in HCV-replicating cells seems to involve phosphatidylinositol 3-kinase (PI3K)/AKT pathway inactivation. Thus, inhibition of the PI3K pathway by LY294002 attenuated LXRα upregulation and HCV replication mediated by lipid accumulation, showing an additive effect when combined with quercetin. Inactivation of the PI3K pathway by quercetin may contribute to the repression of LXRα-dependent lipogenesis and to the inhibition of viral replication induced by the flavonol. Combined, our data suggest that oxidative/nitrosative stress blockage and subsequent modulation of PI3K-LXRα-mediated lipogenesis might contribute to the inhibitory effect of quercetin on HCV replication.

  11. Modulation of the tumor microenvironment and inhibition of EGF/EGFR pathway: novel anti-tumor mechanisms of Cannabidiol in breast cancer.

    PubMed

    Elbaz, Mohamad; Nasser, Mohd W; Ravi, Janani; Wani, Nissar A; Ahirwar, Dinesh K; Zhao, Helong; Oghumu, Steve; Satoskar, Abhay R; Shilo, Konstantin; Carson, William E; Ganju, Ramesh K

    2015-04-01

    The anti-tumor role and mechanisms of Cannabidiol (CBD), a non-psychotropic cannabinoid compound, are not well studied especially in triple-negative breast cancer (TNBC). In the present study, we analyzed CBD's anti-tumorigenic activity against highly aggressive breast cancer cell lines including TNBC subtype. We show here -for the first time-that CBD significantly inhibits epidermal growth factor (EGF)-induced proliferation and chemotaxis of breast cancer cells. Further studies revealed that CBD inhibits EGF-induced activation of EGFR, ERK, AKT and NF-kB signaling pathways as well as MMP2 and MMP9 secretion. In addition, we demonstrated that CBD inhibits tumor growth and metastasis in different mouse model systems. Analysis of molecular mechanisms revealed that CBD significantly inhibits the recruitment of tumor-associated macrophages in primary tumor stroma and secondary lung metastases. Similarly, our in vitro studies showed a significant reduction in the number of migrated RAW 264.7 cells towards the conditioned medium of CBD-treated cancer cells. The conditioned medium of CBD-treated cancer cells also showed lower levels of GM-CSF and CCL3 cytokines which are important for macrophage recruitment and activation. In summary, our study shows -for the first time-that CBD inhibits breast cancer growth and metastasis through novel mechanisms by inhibiting EGF/EGFR signaling and modulating the tumor microenvironment. These results also indicate that CBD can be used as a novel therapeutic option to inhibit growth and metastasis of highly aggressive breast cancer subtypes including TNBC, which currently have limited therapeutic options and are associated with poor prognosis and low survival rates.

  12. Cyclic GMP/PKG-dependent inhibition of TRPC6 channel activity and expression negatively regulates cardiomyocyte NFAT activation Novel mechanism of cardiac stress modulation by PDE5 inhibition.

    PubMed

    Koitabashi, Norimichi; Aiba, Takeshi; Hesketh, Geoffrey G; Rowell, Janelle; Zhang, Manling; Takimoto, Eiki; Tomaselli, Gordon F; Kass, David A

    2010-04-01

    Increased cyclic GMP from enhanced synthesis or suppressed catabolism (e.g. PDE5 inhibition by sildenafil, SIL) activates protein kinase G (PKG) and blunts cardiac pathological hypertrophy. Suppressed calcineurin (Cn)-NFAT (nuclear factor of activated T-cells) signaling appears to be involved, though it remains unclear how this is achieved. One potential mechanism involves activation of Cn/NFAT by calcium entering via transient receptor potential canonical (TRPC) channels (notably TRPC6). Here, we tested the hypothesis that PKG blocks Cn/NFAT activation by modifying and thus inhibiting TRPC6 current to break the positive feedback loop involving NFAT and NFAT-dependent TRPC6 upregulation. TRPC6 expression rose with pressure-overload in vivo, and angiotensin (ATII) or endothelin (ET1) stimulation in neonatal and adult cardiomyocytes in vitro. 8Br-cGMP and SIL reduced ET1-stimulated TRPC6 expression and NFAT dephosphorylation (activity). TRPC6 upregulation was absent if its promoter was mutated with non-functional NFAT binding sites, whereas constitutively active NFAT triggered TRPC6 expression that was not inhibited by SIL. PKG phosphorylated TRPC6, and both T70 and S322 were targeted. Both sites were functionally relevant, as 8Br-cGMP strongly suppressed current in wild-type TRPC6 channels, but not in those with phospho-silencing mutations (T70A, S322A or S322Q). NFAT activation and increased protein synthesis stimulated by ATII or ET1 was blocked by 8Br-cGMP or SIL. However, transfection with T70A or S322Q TRPC6 mutants blocked this inhibitory effect, whereas phospho-mimetic mutants (T70E, S322E, and both combined) suppressed NFAT activation. Thus PDE5-inhibition blocks TRPC6 channel activation and associated Cn/NFAT activation signaling by PKG-dependent channel phosphorylation.

  13. Brassinin inhibits STAT3 signaling pathway through modulation of PIAS-3 and SOCS-3 expression and sensitizes human lung cancer xenograft in nude mice to paclitaxel

    PubMed Central

    Lee, Jong Hyun; Kim, Chulwon; Sethi, Gautam; Ahn, Kwang Seok

    2015-01-01

    Persistent phosphorylation of signal transducers and activators of transcription 3 (STAT3) is frequently observed in tumor cells. We found that brassinin (BSN) suppressed both constitutive and IL-6-inducible STAT3 activation in lung cancer cells. Moreover, BSN induced PIAS-3 protein and mRNA, whereas the expression of SOCS-3 was reduced. Knockdown of PIAS-3 by small interfering RNA prevented inhibition of STAT3 and cytotoxicity by BSN. Overexpression of SOCS-3 in BSN-treated cells increased STAT3 phosphorylation and cell viability. BSN down-regulated STAT3-regulated gene products, inhibited proliferation, invasion, as well as induced apoptosis. Most importantly, when administered intraperitoneally, combination of BSN and paclitaxel significantly decreased the tumor development in a xenograft lung cancer mouse model associated with down-modulation of phospho-STAT3, Ki-67 and CD31. We suggest that BSN inhibits STAT3 signaling through modulation of PIAS-3 and SOCS-3, thereby attenuating tumor growth and increasing sensitivity to paclitaxel. PMID:25788267

  14. The inhibition/excitation ratio related to task-induced oscillatory modulations during a working memory task: A multtimodal-imaging study using MEG and MRS.

    PubMed

    Takei, Yuichi; Fujihara, Kazuyuki; Tagawa, Minami; Hironaga, Naruhito; Near, Jamie; Kasagi, Masato; Takahashi, Yumiko; Motegi, Tomokazu; Suzuki, Yusuke; Aoyama, Yoshiyuki; Sakurai, Noriko; Yamaguchi, Miho; Tobimatsu, Shozo; Ujita, Koichi; Tsushima, Yoshito; Narita, Kosuke; Fukuda, Masato

    2016-03-01

    Detailed studies on the association between neural oscillations and the neurotransmitters gamma-aminobutyric acid (GABA) and glutamate have been performed in vitro. In addition, recent functional magnetic resonance imaging studies have characterized these neurotransmitters in task-induced deactivation processes during a working memory (WM) task. However, few studies have investigated the relationship between these neurotransmitters and task-induced oscillatory changes in the human brain. Here, using combined magnetoencephalography (MEG) and magnetic resonance spectroscopy (MRS), we investigated the modulation of GABA and glutamate + glutamine (Glx) concentrations related to task-induced oscillations in neural activity during a WM task. We first acquired resting-state MRS and MEG data from 20 healthy male volunteers using the n-back task. Time-frequency analysis was employed to determine the power induced during the encoding and retention phases in perigenual anterior cingulate cortex (pg-ACC), mid-ACC, and occipital cortex (OC). Statistical analysis showed that increased WM load was associated with task-induced oscillatory modulations (TIOMs) of the theta-gamma band relative to the zero-back condition (TIOM0B) in each volume of interest during the encoding phase of the n-back task. The task-induced oscillatory modulations in the two-back condition relative to the zero-back condition (TIOM2B-0B) were negatively correlated with the percent rate change of the correct hit rate for 2B-0B, but positively correlated with GABA/Glx. The positive correlation between TIOM2B-0B and GABA/Glx during the WM task indicates the importance of the inhibition/excitation ratio. In particular, a low inhibition/excitation ratio is essential for the efficient inhibition of irrelevant neural activity, thus producing precise task performance. PMID:26780573

  15. Adult hippocampal neurogenesis and pattern separation in DG: a role for feedback inhibition in modulating sparseness to govern population-based coding

    PubMed Central

    McAvoy, Kathleen; Besnard, Antoine; Sahay, Amar

    2015-01-01

    The dentate gyrus (DG) of mammals harbors neural stem cells that generate new dentate granule cells (DGCs) throughout life. Behavioral studies using the contextual fear discrimination paradigm have found that selectively augmenting or blocking adult hippocampal neurogenesis enhances or impairs discrimination under conditions of high, but not low, interference suggestive of a role in pattern separation. Although contextual discrimination engages population-based coding mechanisms underlying pattern separation such as global remapping in the DG and CA3, how adult hippocampal neurogenesis modulates pattern separation in the DG is poorly understood. Here, we propose a role for adult-born DGCs in re-activation coupled modulation of sparseness through feed-back inhibition to govern global remapping in the DG. PMID:26347621

  16. Centchroman inhibits proliferation of head and neck cancer cells through the modulation of PI3K/mTOR Pathway

    SciTech Connect

    Srivastava, Vikas Kumar; Gara, Rishi Kumar; Bhatt, M.L.B.; Sahu, D.P.; Mishra, Durga Prasad

    2011-01-07

    Research highlights: {yields} Centchroman (CC) inhibits cellular proliferation in HNSCC cells through the dual inhibition of PI3/mTOR pathway. {yields} CC treatment also inhibits STAT3 activation and alters expression of proteins involved in cell cycle regulation and DNA repair response in HNSCC cells. {yields} CC exhibits anti-proliferative activity in a variety of non-HNSCC cancer cell lines and is devoid of cytotoxicity to normal cell types of diverse origins. -- Abstract: Centchroman (CC; 67/20; INN: Ormeloxifene) is a non-steroidal antiestrogen extensively used as a female contraceptive in India. In the present study, we report the anti-proliferative effect of CC in head and neck squamous cell carcinoma (HNSCC) cells. CC inhibited cell proliferation in a dose dependent manner at 24 h of treatment. Further studies showed that CC treatment induced apoptosis, inhibited Akt/mTOR and signal transducers and activators of transcription protein 3 (STAT3) signaling, altered proteins associated with cell cycle regulation and DNA damage and inhibited colony forming efficiency of HNSCC cells. In addition, CC displayed anti-proliferative activity against a variety of non-HNSCC cell lines of diverse origin. The ability of CC to serve as a dual-inhibitor of Akt/mTOR and STAT3 signaling warrants further studies into its role as a therapeutic strategy against HNSCC.

  17. Curcumin inhibits the invasion of lung cancer cells by modulating the PKCα/Nox-2/ROS/ATF-2/MMP-9 signaling pathway.

    PubMed

    Fan, Zhigang; Duan, Xiaoyi; Cai, Hui; Wang, Li; Li, Min; Qu, Jingkun; Li, Wanjun; Wang, Yongheng; Wang, Jiansheng

    2015-08-01

    Invasion and metastasis are the major causes of tumor-related mortality in lung cancer. It is believed that curcumin is an effective drug possessing anti-invasive and anti-metastatic activities in the treatment of cancer. However, the specific mechanisms remain unclear. In the present study, we investigated whether the PKCα/Nox-2/ATF-2/MMP-9 signaling pathway is involved in the invasive behavior of lung cancer and whether curcumin could inhibit invasion by modulating this pathway. The cytotoxic effect of curcumin was evaluated by MTT assay and the capacity of invasion was assessed by Transwell assay. siRNA and plasmid transfection techniques were used to study the function of targeted genes. Real-time PCR and western blot analysis were used to evaluate the expression levels of PKCα, Nox-2, MMP-9 and the phosphorylation of ATF-2. The results showed that curcumin inhibited the proliferation and invasion of A549 cells in a dose-dependent manner. Overexpression of MMP-9 enhanced the invasion of A549 cells. However, inhibition of MMP-9 by siRNA or curcumin suppressed cell invasion. Moreover, we also demonstrated the catalytic role of PKCα in expression of MMP-9 and cellular invasion in A549 cells, which was dependent on the expression of Nox-2 and phosphorylation of ATF-2. Finally, we also showed that curcumin dose-dependently reduced the expression of PKCα, P47phox, Nox-2 and phosphorylated ATF-2, as well as intracellular ROS generation, suggesting the inhibitory effect of curcumin on the activation of the PKCα/Nox-2/ROS/ATF-2 pathway. In conclusion, the PKCα/Nox-2/ROS/ATF-2/MMP-9 signaling pathway is activated in lung cancer A549 cells, which could be modulated by curcumin to inhibit cell invasiveness.

  18. Inhibition of Fatty Acid Oxidation Modulates Immunosuppressive Functions of Myeloid-Derived Suppressor Cells and Enhances Cancer Therapies.

    PubMed

    Hossain, Fokhrul; Al-Khami, Amir A; Wyczechowska, Dorota; Hernandez, Claudia; Zheng, Liqin; Reiss, Krzystoff; Valle, Luis Del; Trillo-Tinoco, Jimena; Maj, Tomasz; Zou, Weiping; Rodriguez, Paulo C; Ochoa, Augusto C

    2015-11-01

    Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T-cell immunity and promoting malignant cell proliferation and migration. The therapeutic potential of blocking MDSC in tumors has been limited by their heterogeneity, plasticity, and resistance to various chemotherapy agents. Recent studies have highlighted the role of energy metabolic pathways in the differentiation and function of immune cells; however, the metabolic characteristics regulating MDSC remain unclear. We aimed to determine the energy metabolic pathway(s) used by MDSC, establish its impact on their immunosuppressive function, and test whether its inhibition blocks MDSC and enhances antitumor therapies. Using several murine tumor models, we found that tumor-infiltrating MDSC (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by an increased mitochondrial mass, upregulation of key FAO enzymes, and increased oxygen consumption rate. Pharmacologic inhibition of FAO blocked immune inhibitory pathways and functions in T-MDSC and decreased their production of inhibitory cytokines. FAO inhibition alone significantly delayed tumor growth in a T-cell-dependent manner and enhanced the antitumor effect of adoptive T-cell therapy. Furthermore, FAO inhibition combined with low-dose chemotherapy completely inhibited T-MDSC immunosuppressive effects and induced a significant antitumor effect. Interestingly, a similar increase in fatty acid uptake and expression of FAO-related enzymes was found in human MDSC in peripheral blood and tumors. These results support the possibility of testing FAO inhibition as a novel approach to block MDSC and enhance various cancer therapies.

  19. Inhibition of Fatty Acid Oxidation Modulates Immunosuppressive Functions of Myeloid-Derived Suppressor Cells and Enhances Cancer Therapies

    PubMed Central

    Hossain, Fokhrul; Al-Khami, Amir A.; Wyczechowska, Dorota; Hernandez, Claudia; Zheng, Liqin; Reiss, Krzystoff; Del Valle, Luis; Trillo-Tinoco, Jimena; Maj, Tomasz; Zou, Weiping; Rodriguez, Paulo C.; Ochoa, Augusto C.

    2015-01-01

    Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T-cell immunity and promoting malignant cell proliferation and migration. The therapeutic potential of blocking MDSCs in tumors has been limited by their heterogeneity, plasticity, and resistance to various chemotherapy agents. Recent studies have highlighted the role of energy metabolic pathways in the differentiation and function of immune cells; however, the metabolic characteristics regulating MDSCs remain unclear. We aimed to determine the energy metabolic pathway(s) used by MDSCs, establish its impact on their immunosuppressive function, and test whether its inhibition blocks MDSCs and enhances antitumor therapies. Using several murine tumor models, we found that tumor-infiltrating MDSCs (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by an increased mitochondrial mass, upregulation of key FAO enzymes, and increased oxygen consumption rate. Pharmacologic inhibition of FAO blocked immune inhibitory pathways and functions in T-MDSCs and decreased their production of inhibitory cytokines. FAO inhibition alone significantly delayed tumor growth in a T cell-dependent manner and enhanced the antitumor effect of adoptive T-cell therapy. Furthermore, FAO inhibition combined with low-dose chemotherapy completely inhibited T-MDSCs immunosuppressive effects and induced a significant antitumor effect. Interestingly, a similar increase in fatty acid uptake and expression of FAO-related enzymes was found in human MDSCs in peripheral blood and tumors. These results support the possibility of testing FAO inhibition as a novel approach to block MDSCs and enhance various cancer therapies. PMID:26025381

  20. Alpha-amylase and alpha-glucosidase inhibition is differentially modulated by fucoidan obtained from Fucus vesiculosus and Ascophyllum nodosum.

    PubMed

    Kim, Kyung-Tae; Rioux, Laurie-Eve; Turgeon, Sylvie L

    2014-02-01

    Fucoidan is a water-soluble, negatively charged, biologically active polysaccharide found in great abundance in brown marine algae. However, the inhibition of α-amylase and α-glucosidase by fucoidan derived from two algal species (Ascophyllum nodosum and Fucus vesiculosus) harvested at different periods (accounting for seasonal and yearly variations) has never been investigated. It was found that fucoidans inhibited α-glucosidase differently, depending on the algal species from which it was extracted and the algae's season of harvest. Fucoidan extracted from A. nodosum was a more potent inhibitor of α-glucosidase, with an IC50 ranging from 0.013 to 0.047 mg/mL, than the inhibition by fucoidan extracted from F. vesiculosus (IC50=0.049 mg/mL). In contrast, fucoidan extracted from F. vesiculosus did not inhibit α-amylase activity, while fucoidan from A. nodosum decreased α-amylase activity by 7-100% at 5 mg/mL depending upon the algae harvest period. An IC50 of 0.12-4.64 mg/mL for fucoidan from A. nodosum was found for the α-amylase inhibition. The ability of fucoidan to inhibit α-amylase and α-glucosidase thus varies according to the algae species and harvest period. A. nodosum is more suitable than F. vesiculosus as a source of fucoidan to inhibit α-amylase and α-glucosidase activities. Their potential benefits towards Type 2 diabetes management should be further investigated. PMID:24388677

  1. Rooibos flavonoids inhibit the activity of key adrenal steroidogenic enzymes, modulating steroid hormone levels in H295R cells.

    PubMed

    Schloms, Lindie; Swart, Amanda C

    2014-03-24

    Major rooibos flavonoids--dihydrochalcones, aspalathin and nothofagin, flavones--orientin and vitexin, and a flavonol, rutin, were investigated to determine their influence on the activity of adrenal steroidogenic enzymes, 3β-hydroxysteroid dehydrogenase (3βHSD2) and cytochrome P450 (P450) enzymes, P450 17α-hydroxylase/17,20-lyase (CYP17A1), P450 21-hydroxylase (CYP21A2) and P450 11β-hydroxylase (CYP11B1). All the flavonoids inhibited 3βHSD2 and CYP17A1 significantly, while the inhibition of downstream enzymes, CYP21A2 and CYP11B1, was both substrate and flavonoid specific. The dihydrochalcones inhibited the activity of CYP21A2, but not that of CYP11B1. Although rutin, orientin and vitexin inhibited deoxycortisol conversion by CYP11B1 significantly, inhibition of deoxycorticosterone was <20%. These three flavonoids were unable to inhibit CYP21A2, with negligible inhibition of deoxycortisol biosynthesis only. Rooibos inhibited substrate conversion by CYP17A1 and CYP21A2, while the inhibition of other enzyme activities was <20%. In H295R cells, rutin had the greatest inhibitory effect on steroid production upon forskolin stimulation, reducing total steroid output 2.3-fold, while no effect was detected under basal conditions. Nothofagin and vitexin had a greater inhibitory effect on overall steroid production compared to aspalathin and orientin, respectively. The latter compounds contain two hydroxyl groups on the B ring, while nothofagin and vitexin contain a single hydroxyl group. In addition, all of the flavonoids are glycosylated, albeit at different positions--dihydrochalcones at C3' and flavones at C8 on ring A, while rutin, a larger molecule, has a rutinosyl moiety at C3 on ring C. Structural differences regarding the number and position of hydroxyl and glucose moieties as well as structural flexibility could indicate different mechanisms by which these flavonoids influence the activity of adrenal steroidogenic enzymes.

  2. Inhibition of STAT3 reverses alkylator resistance through modulation of the AKT and β-catenin signaling pathways.

    PubMed

    Wang, Yongzhi; Chen, Lingchao; Bao, Zhaoshi; Li, Shouwei; You, Gan; Yan, Wei; Shi, Zhendong; Liu, Yanwei; Yang, Pei; Zhang, Wei; Han, Lei; Kang, Chunsheng; Jiang, Tao

    2011-11-01

    Activation of signal transducer and activator of transcription 3 (STAT3) is associated with poor clinical outcome of glioblastoma (GBM). However, the role of STAT3 in resistance to alkylator-based chemotherapy remains unknown. Here, we retrospectively analyzed the phosphorylated STAT3 (p-STAT3) profile of 68 GBM patients receiving alkylator therapy, identifying p-STAT3 as an independent unfavorable prognostic factor for progression-free and overall survival. Additionally, elevated p-STAT3 expression correlated with resistance to alkylator therapy. In vitro analysis revealed that U251 and U87 human glioma cells were refractory to treatment with the common alkylating agent temozolomide (TMZ), with only a modest impact on AKT and β-catenin activation in the context of high p-STAT3. Inhibition of STAT3 in these cells significantly enhanced the effect of TMZ. Inhibition of STAT3 dramatically decreased the IC50 of TMZ, increasing TMZ-induced apoptosis while up-regulating expression of Bcl-2 and down-regulating expression of Bax. Furthermore, inhibition of STAT3 increased TMZ-induced G₀-G₁ arrest and decreased Cyclin D1 expression compared to TMZ alone. Together, these results indicate that inhibition of STAT3 sensitizes glioma cells to TMZ, at least in part, by blocking the p-AKT and β-catenin pathways. These findings strongly support the hypothesis that STAT3 inhibition significantly improves the clinical efficacy of alkylating agents.

  3. D1 and D2 Inhibitions of the Soleus H-Reflex Are Differentially Modulated during Plantarflexion Force and Position Tasks

    PubMed Central

    Magalhães, Fernando Henrique; Elias, Leonardo Abdala; da Silva, Cristiano Rocha; de Lima, Felipe Fava; de Toledo, Diana Rezende; Kohn, André Fabio

    2015-01-01

    Presynaptic inhibition (PSI) has been shown to modulate several neuronal pathways of functional relevance by selectively gating the connections between sensory inputs and spinal motoneurons, thereby regulating the contribution of the stretch reflex circuitry to the ongoing motor activity. In this study, we investigated whether a differential regulation of Ia afferent inflow by PSI may be associated with the performance of two types of plantarflexion sensoriomotor tasks. The subjects (in a seated position) controlled either: 1) the force level exerted by the foot against a rigid restraint (force task, FT); or 2) the angular position of the ankle when sustaining inertial loads (position task, PT) that required the same level of muscle activation observed in FT. Subjects were instructed to maintain their force/position at target levels set at ~10% of maximum isometric voluntary contraction for FT and 90° for PT, while visual feedback of the corresponding force/position signals were provided. Unconditioned H-reflexes (i.e. control reflexes) and H-reflexes conditioned by electrical pulses applied to the common peroneal nerve with conditioning-to-test intervals of 21 ms and 100 ms (corresponding to D1 and D2 inhibitions, respectively) were evoked in a random fashion. A significant main effect for the type of the motor task (FT vs PT) (p = 0.005, η2p = 0.603) indicated that PTs were undertaken with lower levels of Ia PSI converging onto the soleus motoneuron pool. Additionally, a significant interaction between the type of inhibition (D1 vs D2) and the type of motor task (FT vs PT) (p = 0.038, η2p = 0.395) indicated that D1 inhibition was associated with a significant reduction in PSI levels from TF to TP (p = 0.001, η2p = 0.731), whereas no significant difference between the tasks was observed for D2 inhibition (p = 0.078, η2p = 0.305). These results suggest that D1 and D2 inhibitions of the soleus H-reflex are differentially modulated during the performance of

  4. K-Ras4B phosphorylation at Ser181 is inhibited by calmodulin and modulates K-Ras activity and function.

    PubMed

    Alvarez-Moya, B; López-Alcalá, C; Drosten, M; Bachs, O; Agell, N

    2010-11-01

    Fine tuning of Ras activity is widely known as a mechanism to induce different cellular responses. Recently, we have shown that calmodulin (CaM) binds to K-Ras and that K-Ras phosphorylation inhibits its interaction with CaM. In this study we report that CaM inhibits K-Ras phosphorylation at Ser181 by protein kinase C (PKC) in vivo, and this is a mechanism to modulate K-Ras activity and signaling. Although CaM inhibition increased the activation of endogenous K-Ras, PKC inhibition decreased its activation status. We demonstrate that K-Ras phosphorylation decreased susceptibility to p120GAP activity. Accordingly, we also observed that non-phosphorylable K-Ras mutant exhibits a less sustained activation profile and do not efficiently activate AKT at low growth factor doses compared with wild-type K-Ras. It is interesting that the physiological responses induced by K-Ras are affected by this phosphorylation; when K-Ras cannot be phosphorylated it exhibits a remarkably decreased ability to stimulate proliferation in non-saturated serum conditions. Finally, we demonstrate that phosphorylation also regulates oncogenic K-Ras functions, as focus formation capacity, mobility and apoptosis resistance upon adriamycin treatment of cells expressing oncogenic K-Ras that cannot be phosphorylated are highly compromised. Moreover, at low serum concentration proliferation and survival is practically inhibited when cells cannot phosphorylate oncogenic K-Ras. In this condition, K-Ras phosphorylation is essential to ensure a proper activation of mitogen-activated protein kinase and PI3K/AKT pathways. In summary, our findings suggest that the interplay between CaM interaction and PKC phosphorylation is essential to regulate non-oncogenic and oncogenic K-Ras activity and functionality.

  5. Modulating Radiation Resistance by Inhibiting Ribonucleotide Reductase in Cancers with Virally or Mutationally Silenced p53 Protein

    PubMed Central

    Kunos, Charles A.; Chiu, Song-mao; Pink, John; Kinsella, Timothy J.

    2009-01-01

    Therapeutic ionizing radiation damages DNA, increasing p53-regulated ribonucleotide reductase (RNR) activity required for de novo synthesis of the deoxyribonucleotide triphosphates used during DNA repair. This study investigated the pharmacological inhibition of RNR in cells of virally or mutationally silenced p53 cancer cell lines using 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine® NSC #663249), a chemotherapeutic radiosensitizer that equally inhibits RNR M2 and p53R2 small subunits. The effects of 3-AP on RNR inhibition and resulting radiosensitization were evaluated in cervical (CaSki, HeLa and C33-a) and colon (RKO, RKO-E6) cancer cells. 3-AP treatment significantly enhanced radiation-related cytotoxicity in cervical and colon cancer cells. 3-AP treatment significantly decreased RNR activity, caused prolonged radiation-induced DNA damage, and resulted in an extended G1/S-phase cell cycle arrest in all cell lines. Similar effects were observed in both RKO and RKO-E6 cells, suggesting a p53-independent mechanism of radiosensitization. We conclude that inhibition of ribonucleotide reductase by 3-AP enhances radiation-mediated cytotoxicity independent of p53 regulation by impairing repair processes that rely on deoxyribonucleotide production, thereby substantially increasing the radiation sensitivity of human cancers. PMID:19929413

  6. Acetyl-CoA carboxylase inhibition by ND-630 reduces hepatic steatosis, improves insulin sensitivity, and modulates dyslipidemia in rats

    PubMed Central

    Harriman, Geraldine; Greenwood, Jeremy; Bhat, Sathesh; Huang, Xinyi; Wang, Ruiying; Paul, Debamita; Tong, Liang; Saha, Asish K.; Westlin, William F.; Kapeller, Rosana; Harwood, H. James

    2016-01-01

    Simultaneous inhibition of the acetyl-CoA carboxylase (ACC) isozymes ACC1 and ACC2 results in concomitant inhibition of fatty acid synthesis and stimulation of fatty acid oxidation and may favorably affect the morbidity and mortality associated with obesity, diabetes, and fatty liver disease. Using structure-based drug design, we have identified a series of potent allosteric protein–protein interaction inhibitors, exemplified by ND-630, that interact within the ACC phosphopeptide acceptor and dimerization site to prevent dimerization and inhibit the enzymatic activity of both ACC isozymes, reduce fatty acid synthesis and stimulate fatty acid oxidation in cultured cells and in animals, and exhibit favorable drug-like properties. When administered chronically to rats with diet-induced obesity, ND-630 reduces hepatic steatosis, improves insulin sensitivity, reduces weight gain without affecting food intake, and favorably affects dyslipidemia. When administered chronically to Zucker diabetic fatty rats, ND-630 reduces hepatic steatosis, improves glucose-stimulated insulin secretion, and reduces hemoglobin A1c (0.9% reduction). Together, these data suggest that ACC inhibition by representatives of this series may be useful in treating a variety of metabolic disorders, including metabolic syndrome, type 2 diabetes mellitus, and fatty liver disease. PMID:26976583

  7. Inhibition of LINE-1 retrotransposon-encoded reverse transcriptase modulates the expression of cell differentiation genes in breast cancer cells.

    PubMed

    Patnala, Radhika; Lee, Sung-Hun; Dahlstrom, Jane E; Ohms, Stephen; Chen, Long; Dheen, S Thameem; Rangasamy, Danny

    2014-01-01

    Long Interspersed Elements (L1 elements) are biologically active retrotransposons that are capable of autonomous replication using their own reverse transcriptase (RT) enzyme. Expression of the normally repressed RT has been implicated in cancer cell growth. However, at present, little is known about the expression of L1-encoded RT activity or the molecular changes that are associated with RT activity in the development of breast cancer. Here, we report that RT activity is widespread in breast cancer cells. The expression of RT protein decreased markedly in breast cancer cells after treatment with the antiretroviral drug, efavirenz. While the majority of cells showed a significant reduction in proliferation, inhibition of RT was also accompanied by cell-specific differences in morphology. MCF7 cells displayed elongated microtubule extensions that adhered tightly to their substrate, while a large fraction of the T47D cells that we studied formed long filopodia projections. These morphological changes were reversible upon cessation of RT inhibition, confirming their dependence on RT activity. We also carried out gene expression profiling with microarrays and determined the genes that were differentially expressed during the process of cellular differentiation. Genes involved in proliferation, cell migration, and invasive activity were repressed in RT-inhibited cells. Concomitantly, genes involved in cell projection, formation of vacuolar membranes, and cell-to-cell junctions were significantly upregulated in RT-inhibited cells. qRT-PCR examination of the mRNA expression of these genes in additional cell lines yielded close correlation between their differential expression and the degree of cellular differentiation. Our study demonstrates that the inhibition of L1-encoded RT can reduce the rate of proliferation and promote differentiation of breast cancer cells. Together, these results provide a direct functional link between the expression of L1 retrotransposons and

  8. Combined dual effect of modulation of human neutrophils' oxidative burst and inhibition of colon cancer cells proliferation by hydroxycinnamic acid derivatives.

    PubMed

    Tavares-da-Silva, Elisiário J; Varela, Carla L; Pires, Ana S; Encarnação, João C; Abrantes, Ana M; Botelho, Maria F; Carvalho, Rui A; Proença, Carina; Freitas, Marisa; Fernandes, Eduarda; Roleira, Fernanda M F

    2016-08-15

    Colon cancer is one of the most incident cancers in the Western World. While both genetic and epigenetic factors may contribute to the development of colon cancer, it is known that chronic inflammation associated to excessive production of reactive oxygen and nitrogen species by phagocytes may ultimately initiate the multistep process of colon cancer development. Phenolic compounds, which reveal antioxidant and antiproliferative activities in colon cancer cells, can be a good approach to surpass this problem. In this work, hydroxycinnamic amides and the respective acid precursors were tested in vitro for their capacity to modulate human neutrophils' oxidative burst and simultaneously to inhibit growth of colon cancer cells. A phenolic amide derivative, caffeic acid hexylamide (CAHA) (4) was found to be the most active compound in both assays, inhibiting human neutrophils' oxidative burst, restraining the inflammatory process, inhibiting growth of colon cancer cells and triggering mitochondrial dysfunction that leads cancer cells to apoptosis. Altogether, these achievements can contribute to the understanding of the relationship between antioxidant and anticancer activities and based on the structure-activity relationships (SAR) established can be the starting point to find more effective phenolic compounds as anticancer agents.

  9. The natural yeast extract isolated by ethanol precipitation inhibits melanin synthesis by modulating tyrosinase activity and downregulating melanosome transfer.

    PubMed

    Lee, Woo Jin; Rhee, Do Young; Bang, Seung Hyun; Kim, Su Yeon; Won, Chong Hyun; Lee, Mi Woo; Choi, Jee Ho; Chang, Sung Eun

    2015-01-01

    This study was conducted to examine the effects of EP-2, a natural yeast extract isolated by ethanol precipitation from Saccharomyces cerevisiae, on melanogenesis and to determine its underlying mechanism of action. Our results show that although EP-2 is not a direct tyrosinase inhibitor, when EP-2 was added to the culture media of B16F10 melanoma cells, intracellular tyrosinase activity was decreased. However, EP-2 had no effect on the expression of microphthalmia-associated transcription factor or tyrosinase. EP-2 was found to inhibit melanogenesis and melanosome transfer when it was added to melanocytes and keratinocytes in coculture. In addition, protease-activated receptor 2, a key protein associated with melanosome transfer from melanocytes to keratinocytes, was downregulated in the presence of EP-2. In conclusion, EP-2 is a potent inhibitor of melanogenesis and its hypomelanogenic effect is related to the inhibition of tyrosinase activity and transfer of melanosomes.

  10. Antioxidative Dietary Compounds Modulate Gene Expression Associated with Apoptosis, DNA Repair, Inhibition of Cell Proliferation and Migration

    PubMed Central

    Wang, Likui; Gao, Shijuan; Jiang, Wei; Luo, Cheng; Xu, Maonian; Bohlin, Lars; Rosendahl, Markus; Huang, Wenlin

    2014-01-01

    Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2) called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE), which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix) polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen) and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair. PMID:25226533

  11. Inhibition of Pyruvate Dehydrogenase Kinase 2 Protects Against Hepatic Steatosis Through Modulation of Tricarboxylic Acid Cycle Anaplerosis and Ketogenesis.

    PubMed

    Go, Younghoon; Jeong, Ji Yun; Jeoung, Nam Ho; Jeon, Jae-Han; Park, Bo-Yoon; Kang, Hyeon-Ji; Ha, Chae-Myeong; Choi, Young-Keun; Lee, Sun Joo; Ham, Hye Jin; Kim, Byung-Gyu; Park, Keun-Gyu; Park, So Young; Lee, Chul-Ho; Choi, Cheol Soo; Park, Tae-Sik; Lee, W N Paul; Harris, Robert A; Lee, In-Kyu

    2016-10-01

    Hepatic steatosis is associated with increased insulin resistance and tricarboxylic acid (TCA) cycle flux, but decreased ketogenesis and pyruvate dehydrogenase complex (PDC) flux. This study examined whether hepatic PDC activation by inhibition of pyruvate dehydrogenase kinase 2 (PDK2) ameliorates these metabolic abnormalities. Wild-type mice fed a high-fat diet exhibited hepatic steatosis, insulin resistance, and increased levels of pyruvate, TCA cycle intermediates, and malonyl-CoA but reduced ketogenesis and PDC activity due to PDK2 induction. Hepatic PDC activation by PDK2 inhibition attenuated hepatic steatosis, improved hepatic insulin sensitivity, reduced hepatic glucose production, increased capacity for β-oxidation and ketogenesis, and decreased the capacity for lipogenesis. These results were attributed to altered enzymatic capacities and a reduction in TCA anaplerosis that limited the availability of oxaloacetate for the TCA cycle, which promoted ketogenesis. The current study reports that increasing hepatic PDC activity by inhibition of PDK2 ameliorates hepatic steatosis and insulin sensitivity by regulating TCA cycle anaplerosis and ketogenesis. The findings suggest PDK2 is a potential therapeutic target for nonalcoholic fatty liver disease.

  12. Cinnamaldehyde inhibits fungal growth and aflatoxin B1 biosynthesis by modulating the oxidative stress response of Aspergillus flavus.

    PubMed

    Sun, Qi; Shang, Bo; Wang, Ling; Lu, Zhisong; Liu, Yang

    2016-02-01

    Cinnamaldehyde (CIN) is a promising natural preservative and generally recognized as safe for commodities as well as consumers. In this work, the antifungal effects of CIN on Aspergillus flavus were evaluated both in solid and in liquid culture conditions. Our results indicated that CIN effectively inhibited radial growth, spore production, mycelium formation, and aflatoxin B1 biosynthesis by A. flavus in a dose-dependent manner. At the concentration of 104 mg L(-1), CIN exposure was able to completely inhibit fungal growth as well as aflatoxin B1 production. Furthermore, the inhibitory activities of CIN were closely connected with the treatment period and the tested fungal species. Compared with the control strains, CIN dose dependently changed the morphology and ultrastructure of mycelium in different degree. Especially, the reduction of hydrogen peroxide was considered to follow the destruction of mitochondrial. Meanwhile, CIN significantly cut the levels of lipid peroxidation and reduced glutathione. The activity of total superoxide dismutase was significantly inhibited after CIN treatment at the end of incubation, whereas the activities of catalase and glutathione peroxidase were opposite. These results indicated that the inhibitory effect of CIN could attribute to oxidative stress alleviation possibly induced by modifications of cellular structure as well as redox status. PMID:26585445

  13. A standardized bamboo leaf extract inhibits monocyte adhesion to endothelial cells by modulating vascular cell adhesion protein-1

    PubMed Central

    Choi, Sunga; Park, Myoung Soo; Lee, Yu Ran; Lee, Young Chul; Kim, Tae Woo; Do, Seon-Gil; Kim, Dong Seon

    2013-01-01

    Bamboo leaves (Phyllostachys pubescens Mazel ex J. Houz (Poacea)) have a long history of food and medical applications in Asia, including Japan and Korea. They have been used as a traditional medicine for centuries. We investigated the mechanism of anti-inflammatory activity of a bamboo leaf extract (BLE) on tumor necrosis factor-alpha (TNF-α)-induced monocyte adhesion in human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs to BLE did not inhibit cell viability or cause morphological changes at concentrations ranging from 1 µg/ml to 1 mg/ml. Treatment with 0.1 mg/ml BLE caused 63% inhibition of monocyte adhesion in TNF-α-activated HUVECs, which was associated with 38.4% suppression of vascular cell adhesion molecule-1 expression. Furthermore, TNF-α-induced reactive oxygen species generation was decreased to 47.9% in BLE treated TNF-α-activated HUVECs. BLE (0.05 mg/ml) also caused about 50% inhibition of interleukin-6 secretion from lipopolysaccharide-stimulated monocyte. The results indicate that BLE may be clinically useful as an anti-inflammatory or anti-oxidant for human cardiovascular disease including atherosclerosis. PMID:23422838

  14. Prepulse inhibition of the startle reflex and its attentional modulation in the human S-ketamine and N,N-dimethyltryptamine (DMT) models of psychosis.

    PubMed

    Heekeren, K; Neukirch, A; Daumann, J; Stoll, M; Obradovic, M; Kovar, K-A; Geyer, M A; Gouzoulis-Mayfrank, E

    2007-05-01

    Patients with schizophrenia exhibit diminished prepulse inhibition (PPI) of the acoustic startle reflex and deficits in the attentional modulation of PPI. Pharmacological challenges with hallucinogens are used as models for psychosis in both humans and animals. Remarkably, in contrast to the findings in schizophrenic patients and in animal hallucinogen models of psychosis, previous studies with healthy volunteers demonstrated increased levels of PPI after administration of low to moderate doses of either the antiglutamatergic hallucinogen ketamine or the serotonergic hallucinogen psilocybin. The aim of the present study was to investigate the influence of moderate and high doses of the serotonergic hallucinogen N,N-dimethyltryptamine (DMT) and the N-methyl-D-aspartate antagonist S-ketamine on PPI and its attentional modulation in humans. Fifteen healthy volunteers were included in a double-blind cross-over study with two doses of DMT and S-ketamine. Effects on PPI and its attentional modulation were investigated. Nine subjects completed both experimental days with the two doses of both drugs. S-ketamine increased PPI in both dosages, whereas DMT had no significant effects on PPI. S-ketamine decreased and DMT tended to decrease startle magnitude. There were no significant effects of either drug on the attentional modulation of PPI. In human experimental hallucinogen psychoses, and even with high, clearly psychotogenic doses of DMT or S-ketamine, healthy subjects failed to exhibit the predicted attenuation of PPI. In contrast, PPI was augmented and the startle magnitude was decreased after S-ketamine. These data point to important differences between human hallucinogen models and both animal hallucinogen models of psychosis and naturally occurring schizophrenia.

  15. Inhibition of epithelial-mesenchymal transition in bladder cancer cells via modulation of mTOR signalling.

    PubMed

    Iskender, Banu; Izgi, Kenan; Hizar, Esra; Jauch, Johann; Arslanhan, Aslihan; Yuksek, Esra Hilal; Canatan, Halit

    2016-06-01

    Mounting evidence suggests that signalling cross-talk plays a significant role in the regulation of epithelial-mesenchymal transition (EMT) in cancer cells. However, the complex network regulating the EMT in different cancer types has not been fully described yet which affects the development of novel therapeutic strategies. In the present study, we investigated the signalling pathways involved in EMT of bladder cancer cells and demonstrated the effects of two novel agents in the regulation of EMT. Myrtucommulone-A (MC-A) and thymoquinone (TQ) have been shown to possess anti-cancer properties. However, their targets in the regulation of cancer cell behavior are not well defined. Here, we defined the effects of two putative anti-cancer agents on bladder cancer cell migration and their possible intracellular targets in the regulation of EMT. Our results suggest that MC-A or TQ treatment affected N-cadherin, Snail, Slug, and β-catenin expressions and effectively attenuated mTOR activity. The downstream components in mTOR signalling were also affected. MC-A treatment resulted in the concomitant inhibition of extracellular matrix-regulated protein kinases 1 and 2 (ERK 1/2), p38 mitogen-activated protein kinase (MAPK) and Src activity. On the other hand, TQ treatment increased Src activity while exerting no effect on ERK 1/2 or p38 MAPK activity. Given the stronger inhibition of EMT-related markers in MC-A-treated samples, we concluded that this effect might be due to collective inhibition of multiple signalling pathways which result in a decrease in their cross-talk in bladder cancer cells. Overall, the data in this study proposes novel action mechanisms for MC-A or TQ in bladder cancer cells and highlights the potential use of these active compounds in the regulation of EMT.

  16. Cannabidiol, among Other Cannabinoid Drugs, Modulates Prepulse Inhibition of Startle in the SHR Animal Model: Implications for Schizophrenia Pharmacotherapy.

    PubMed

    Peres, Fernanda F; Levin, Raquel; Almeida, Valéria; Zuardi, Antonio W; Hallak, Jaime E; Crippa, José A; Abilio, Vanessa C

    2016-01-01

    Schizophrenia is a severe psychiatric disorder that involves positive, negative and cognitive symptoms. Prepulse inhibition of startle reflex (PPI) is a paradigm that assesses the sensorimotor gating functioning and is impaired in schizophrenia patients as well as in animal models of this disorder. Recent data point to the participation of the endocannabinoid system in the pathophysiology and pharmacotherapy of schizophrenia. Here, we focus on the effects of cannabinoid drugs on the PPI deficit of animal models of schizophrenia, with greater focus on the SHR (Spontaneously Hypertensive Rats) strain, and on the future prospects resulting from these findings. PMID:27667973

  17. Cannabidiol, among Other Cannabinoid Drugs, Modulates Prepulse Inhibition of Startle in the SHR Animal Model: Implications for Schizophrenia Pharmacotherapy

    PubMed Central

    Peres, Fernanda F.; Levin, Raquel; Almeida, Valéria; Zuardi, Antonio W.; Hallak, Jaime E.; Crippa, José A.; Abilio, Vanessa C.

    2016-01-01

    Schizophrenia is a severe psychiatric disorder that involves positive, negative and cognitive symptoms. Prepulse inhibition of startle reflex (PPI) is a paradigm that assesses the sensorimotor gating functioning and is impaired in schizophrenia patients as well as in animal models of this disorder. Recent data point to the participation of the endocannabinoid system in the pathophysiology and pharmacotherapy of schizophrenia. Here, we focus on the effects of cannabinoid drugs on the PPI deficit of animal models of schizophrenia, with greater focus on the SHR (Spontaneously Hypertensive Rats) strain, and on the future prospects resulting from these findings.

  18. Cannabidiol, among Other Cannabinoid Drugs, Modulates Prepulse Inhibition of Startle in the SHR Animal Model: Implications for Schizophrenia Pharmacotherapy

    PubMed Central

    Peres, Fernanda F.; Levin, Raquel; Almeida, Valéria; Zuardi, Antonio W.; Hallak, Jaime E.; Crippa, José A.; Abilio, Vanessa C.

    2016-01-01

    Schizophrenia is a severe psychiatric disorder that involves positive, negative and cognitive symptoms. Prepulse inhibition of startle reflex (PPI) is a paradigm that assesses the sensorimotor gating functioning and is impaired in schizophrenia patients as well as in animal models of this disorder. Recent data point to the participation of the endocannabinoid system in the pathophysiology and pharmacotherapy of schizophrenia. Here, we focus on the effects of cannabinoid drugs on the PPI deficit of animal models of schizophrenia, with greater focus on the SHR (Spontaneously Hypertensive Rats) strain, and on the future prospects resulting from these findings. PMID:27667973

  19. Behavioral-state modulation of inhibition is context-dependent and cell type specific in mouse visual cortex

    PubMed Central

    Pakan, Janelle MP; Lowe, Scott C; Dylda, Evelyn; Keemink, Sander W; Currie, Stephen P; Coutts, Christopher A; Rochefort, Nathalie L

    2016-01-01

    Cortical responses to sensory stimuli are modulated by behavioral state. In the primary visual cortex (V1), visual responses of pyramidal neurons increase during locomotion. This response gain was suggested to be mediated through inhibitory neurons, resulting in the disinhibition of pyramidal neurons. Using in vivo two-photon calcium imaging in layers 2/3 and 4 in mouse V1, we reveal that locomotion increases the activity of vasoactive intestinal peptide (VIP), somatostatin (SST) and parvalbumin (PV)-positive interneurons during visual stimulation, challenging the disinhibition model. In darkness, while most VIP and PV neurons remained locomotion responsive, SST and excitatory neurons were largely non-responsive. Context-dependent locomotion responses were found in each cell type, with the highest proportion among SST neurons. These findings establish that modulation of neuronal activity by locomotion is context-dependent and contest the generality of a disinhibitory circuit for gain control of sensory responses by behavioral state. DOI: http://dx.doi.org/10.7554/eLife.14985.001 PMID:27552056

  20. Curcumin Promotes Cell Cycle Arrest and Inhibits Survival of Human Renal Cancer Cells by Negative Modulation of the PI3K/AKT Signaling Pathway.

    PubMed

    Zhang, Hao; Xu, Weili; Li, Baolin; Zhang, Kai; Wu, Yudong; Xu, Haidong; Wang, Junyong; Zhang, Jun; Fan, Rui; Wei, Jinxing

    2015-12-01

    Curcumin possesses anti-cancer effects. In the current study, we tested the effect of curcumin on cell proliferation, viability, apoptosis, cell cycle phases, and activation of the PI3K/Akt pathway in the renal cell carcinoma (RCC) cell line RCC-949. We observed that cell proliferation and viability were markedly inhibited by curcumin, while cell apoptosis was promoted. The latter effect was associated with increased expression of Bcl-2 and diminished expression of Bax (both: mRNA and protein). The cells treated with curcumin increasingly went into cell cycle arrest, which was likely mediated by diminished expression of cyclin B1, as seen in curcumin-treated cells. In addition, curcumin decreased activation of the PI3K/AKT signaling pathway. In conclusion, our results demonstrate that curcumin exerts anti-cancer effects by negative modulation of the PI3K/AKT signaling pathway and may represent a promising new drug to treat RCC. PMID:27259310

  1. Antipsychotic-like Effects of M4 Positive Allosteric Modulators Are Mediated by CB2 Receptor-Dependent Inhibition of Dopamine Release.

    PubMed

    Foster, Daniel J; Wilson, Jermaine M; Remke, Daniel H; Mahmood, M Suhaib; Uddin, M Jashim; Wess, Jürgen; Patel, Sachin; Marnett, Lawrence J; Niswender, Colleen M; Jones, Carrie K; Xiang, Zixiu; Lindsley, Craig W; Rook, Jerri M; Conn, P Jeffrey

    2016-09-21

    Muscarinic receptors represent a promising therapeutic target for schizophrenia, but the mechanisms underlying the antipsychotic efficacy of muscarinic modulators are not well understood. Here, we report that activation of M4 receptors on striatal spiny projection neurons results in a novel form of dopaminergic regulation resulting in a sustained depression of striatal dopamine release that is observed more than 30 min after removal of the muscarinic receptor agonist. Furthermore, both the M4-mediated sustained inhibition of dopamine release and the antipsychotic-like efficacy of M4 activators were found to require intact signaling through CB2 cannabinoid receptors. These findings highlight a novel mechanism by which striatal cholinergic and cannabinoid signaling leads to sustained reductions in dopaminergic transmission and concurrent behavioral effects predictive of antipsychotic efficacy. PMID:27618677

  2. d-alpha-tocopherol inhibits collagen alpha 1(I) gene expression in cultured human fibroblasts. Modulation of constitutive collagen gene expression by lipid peroxidation.

    PubMed Central

    Houglum, K; Brenner, D A; Chojkier, M

    1991-01-01

    Ascorbic acid stimulates collagen gene transcription in cultured fibroblasts, and this effect is mediated through the induction of lipid peroxidation by ascorbic acid. Quiescent cultured fibroblasts in the absence of ascorbic acid have a high constitutive level of collagen production, but the mechanisms of collagen gene regulation in this unstimulated state are not known. Because lipid peroxidation also occurs in normal cells, we wondered if lipid peroxidation plays a role in the regulation of basal collagen gene expression. Inhibition of lipid peroxidation in cultured human fibroblasts with d-alpha-tocopherol or methylene blue decreased the synthesis of collagen, the steady-state levels of procollagen alpha 1(I) mRNA and the transcription of the procollagen alpha 1(I) gene. This effect on collagen gene expression was selective and not associated with cellular toxicity. Thus, these experiments suggest a role for lipid peroxidation in the modulation of constitutive collagen gene expression. Images PMID:2040703

  3. Cranberries (Oxycoccus quadripetalus) inhibit lipid metabolism and modulate leptin and adiponectin secretion in 3T3-L1 adipocytes.

    PubMed

    Kowalska, Katarzyna; Olejnik, Anna; Rychlik, Joanna; Grajek, Włodzimierz

    2015-10-15

    It has previously been shown that lyophilized cranberries (LCB) decreased lipid accumulation in 3T3-L1 cells and inhibited preadipocyte differentiation by down-regulation of the expression of key transcription factors (PPARγ, C/EBPα, SREBP1) of the adipogenesis pathway. To elucidate the molecular basis of anti-lipogenic activity of LCB, the expression of several genes involved in lipid metabolism, such as adipocyte fatty acid-binding protein (aP2), lipoprotein lipase (LPL), fatty acid synthase (FAS), hormone sensitive lipase (HSL) and perilipin 1 (PLIN1), was examined in the present study. Additionally, the effects of LCB on adiponectin and leptin expression and protein secretion were also investigated. LCB reduced lipid accumulation during preadipocyte differentiation by down-regulation of the mRNA level of aP2, FAS, LPL, HSL and PLIN1. Moreover, LCB decreased leptin gene expression and increased adiponectin gene expression and protein secretion in a dose-dependent manner. Therefore cranberries could be considered as bioactive factors, which are effective in the inhibition of adipose tissue mass production. PMID:25952883

  4. SENP1 inhibition induces apoptosis and growth arrest of multiple myeloma cells through modulation of NF-κB signaling

    SciTech Connect

    Xu, Jun; Sun, Hui-Yan; Xiao, Feng-Jun; Wang, Hua; Yang, Yang; Wang, Lu; Gao, Chun-Ji; Guo, Zi-Kuan; Wu, Chu-Tse; Wang, Li-Sheng

    2015-05-01

    SUMO/sentrin specific protease 1 (Senp1) is an important regulation protease in the protein sumoylation, which affects the cell cycle, proliferation and differentiation. The role of Senp1 mediated protein desumoylation in pathophysiological progression of multiple myeloma is unknown. In this study, we demonstrated that Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. Lentivirus-mediated Senp1 knockdown triggers apoptosis and reduces viability, proliferation and colony forming ability of MM cells. The NF-κB family members including P65 and inhibitor protein IkBα play important roles in regulation of MM cell survival and proliferation. We further demonstrated that Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation, leading to inactivation of NF-kB signaling in MM cells. These results delineate a key role for Senp1in IL-6 induced proliferation and survival of MM cells, suggesting it may be a potential new therapeutic target in MM. - Highlights: • Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. • Senp1 knockdown triggers apoptosis and reduces proliferation of MM cells. • Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation.

  5. Cranberries (Oxycoccus quadripetalus) inhibit lipid metabolism and modulate leptin and adiponectin secretion in 3T3-L1 adipocytes.

    PubMed

    Kowalska, Katarzyna; Olejnik, Anna; Rychlik, Joanna; Grajek, Włodzimierz

    2015-10-15

    It has previously been shown that lyophilized cranberries (LCB) decreased lipid accumulation in 3T3-L1 cells and inhibited preadipocyte differentiation by down-regulation of the expression of key transcription factors (PPARγ, C/EBPα, SREBP1) of the adipogenesis pathway. To elucidate the molecular basis of anti-lipogenic activity of LCB, the expression of several genes involved in lipid metabolism, such as adipocyte fatty acid-binding protein (aP2), lipoprotein lipase (LPL), fatty acid synthase (FAS), hormone sensitive lipase (HSL) and perilipin 1 (PLIN1), was examined in the present study. Additionally, the effects of LCB on adiponectin and leptin expression and protein secretion were also investigated. LCB reduced lipid accumulation during preadipocyte differentiation by down-regulation of the mRNA level of aP2, FAS, LPL, HSL and PLIN1. Moreover, LCB decreased leptin gene expression and increased adiponectin gene expression and protein secretion in a dose-dependent manner. Therefore cranberries could be considered as bioactive factors, which are effective in the inhibition of adipose tissue mass production.

  6. Small-Molecule Inhibition of Rho/MKL/SRF Transcription in Prostate Cancer Cells: Modulation of Cell Cycle, ER Stress, and Metastasis Gene Networks.

    PubMed

    Evelyn, Chris R; Lisabeth, Erika M; Wade, Susan M; Haak, Andrew J; Johnson, Craig N; Lawlor, Elizabeth R; Neubig, Richard R

    2016-05-28

    Metastasis is the major cause of cancer deaths and control of gene transcription has emerged as a critical contributing factor. RhoA- and RhoC-induced gene transcription via the actin-regulated transcriptional co-activator megakaryocytic leukemia (MKL) and serum response factor (SRF) drive metastasis in breast cancer and melanoma. We recently identified a compound, CCG-1423, which blocks Rho/MKL/SRF-mediated transcription and inhibits PC-3 prostate cancer cell invasion. Here, we undertook a genome-wide expression study in PC-3 cells to explore the mechanism and function of this compound. There was significant overlap in the genes modulated by CCG-1423 and Latrunculin B (Lat B), which blocks the Rho/MKL/SRF pathway by preventing actin polymerization. In contrast, the general transcription inhibitor 5,6-dichloro-1-β-d-ribofuranosyl-1H-benzimidazole (DRB) showed a markedly different pattern. Effects of CCG-1423 and Lat B on gene expression correlated with literature studies of MKL knock-down. Gene sets involved in DNA synthesis and repair, G1/S transition, and apoptosis were modulated by CCG-1423. It also upregulated genes involved in endoplasmic reticulum stress. Targets of the known Rho target transcription factor family E2F and genes related to melanoma progression and metastasis were strongly suppressed by CCG-1423. These results confirm the ability of our compound to inhibit expression of numerous Rho/MKL-dependent genes and show effects on stress pathways as well. This suggests a novel approach to targeting aggressive cancers and metastasis.

  7. HDAC inhibition prevents white matter injury by modulating microglia/macrophage polarization through the GSK3β/PTEN/Akt axis.

    PubMed

    Wang, Guohua; Shi, Yejie; Jiang, Xiaoyan; Leak, Rehana K; Hu, Xiaoming; Wu, Yun; Pu, Hongjian; Li, Wei-Wei; Tang, Bo; Wang, Yun; Gao, Yanqin; Zheng, Ping; Bennett, Michael V L; Chen, Jun

    2015-03-01

    Severe traumatic brain injury (TBI) elicits destruction of both gray and white matter, which is exacerbated by secondary proinflammatory responses. Although white matter injury (WMI) is strongly correlated with poor neurological status, the maintenance of white matter integrity is poorly understood, and no current therapies protect both gray and white matter. One candidate approach that may fulfill this role is inhibition of class I/II histone deacetylases (HDACs). Here we demonstrate that the HDAC inhibitor Scriptaid protects white matter up to 35 d after TBI, as shown by reductions in abnormally dephosphorylated neurofilament protein, increases in myelin basic protein, anatomic preservation of myelinated axons, and improved nerve conduction. Furthermore, Scriptaid shifted microglia/macrophage polarization toward the protective M2 phenotype and mitigated inflammation. In primary cocultures of microglia and oligodendrocytes, Scriptaid increased expression of microglial glycogen synthase kinase 3 beta (GSK3β), which phosphorylated and inactivated phosphatase and tensin homologue (PTEN), thereby enhancing phosphatidylinositide 3-kinases (PI3K)/Akt signaling and polarizing microglia toward M2. The increase in GSK3β in microglia and their phenotypic switch to M2 was associated with increased preservation of neighboring oligodendrocytes. These findings are consistent with recent findings that microglial phenotypic switching modulates white matter repair and axonal remyelination and highlight a previously unexplored role for HDAC activity in this process. Furthermore, the functions of GSK3β may be more subtle than previously thought, in that GSK3β can modulate microglial functions via the PTEN/PI3K/Akt signaling pathway and preserve white matter homeostasis. Thus, inhibition of HDACs in microglia is a potential future therapy in TBI and other neurological conditions with white matter destruction. PMID:25691750

  8. Selective ablation of dorsal horn NK1 expressing cells reveals a modulation of spinal alpha2-adrenergic inhibition of dorsal horn neurones.

    PubMed

    Rahman, Wahida; Suzuki, Rie; Hunt, Stephen P; Dickenson, Anthony H

    2008-06-01

    Activity in descending systems from the brainstem modulates nociceptive transmission through the dorsal horn. Intrathecal injection of the neurotoxin saporin conjugated to SP (SP-SAP) into the lumbar spinal cord results in the selective ablation of NK(1) receptor expressing (NK(1)+ve) neurones in the superficial dorsal horn (lamina I/III). Loss of these NK(1)+ve neurones attenuates excitability of deep dorsal horn neurones due to a disruption of both intrinsic spinal circuits and a spino-bulbo-spinal loop, which activates a descending excitatory drive, mediated through spinal 5HT(3) receptors. Descending inhibitory pathways also modulate spinal activity and hence control the level of nociceptive transmission relayed to higher centres. To ascertain the spinal origins of the major descending noradrenergic inhibitory pathway we studied the effects of a selective alpha2-adrenoceptor antagonist, atipamezole, on neuronal activity in animals pre-treated with SP-SAP. Intrathecal application of atipamezole dose dependently facilitated the mechanically evoked neuronal responses of deep dorsal horn neurones to low intensity von Frey hairs (5-15 g) and noxious thermal (45-50 degrees C) evoked responses in SAP control animals indicating a physiological alpha2-adrenoceptor control. This facilitatory effect of atipamezole was lost in the SP-SAP treated group. These data suggest that activity within noradrenergic pathways have a dependence on dorsal horn NK(1)+ve cells. Further, noradrenergic descending inhibition may in part be driven by lamina I/III (NK(1)+ve) cells, and mediated via spinal alpha2-adrenoceptor activation. Since the same neuronal population drives descending facilitation and inhibition, the reduced excitability of lamina V/VI WDR neurones seen after loss of these NK(1)+ve neurones indicates a dominant role of descending facilitation. PMID:18462764

  9. Small-Molecule Inhibition of Rho/MKL/SRF Transcription in Prostate Cancer Cells: Modulation of Cell Cycle, ER Stress, and Metastasis Gene Networks

    PubMed Central

    Evelyn, Chris R.; Lisabeth, Erika M.; Wade, Susan M.; Haak, Andrew J.; Johnson, Craig N.; Lawlor, Elizabeth R.; Neubig, Richard R.

    2016-01-01

    Metastasis is the major cause of cancer deaths and control of gene transcription has emerged as a critical contributing factor. RhoA- and RhoC-induced gene transcription via the actin-regulated transcriptional co-activator megakaryocytic leukemia (MKL) and serum response factor (SRF) drive metastasis in breast cancer and melanoma. We recently identified a compound, CCG-1423, which blocks Rho/MKL/SRF-mediated transcription and inhibits PC-3 prostate cancer cell invasion. Here, we undertook a genome-wide expression study in PC-3 cells to explore the mechanism and function of this compound. There was significant overlap in the genes modulated by CCG-1423 and Latrunculin B (Lat B), which blocks the Rho/MKL/SRF pathway by preventing actin polymerization. In contrast, the general transcription inhibitor 5,6-dichloro-1-β-d-ribofuranosyl-1H-benzimidazole (DRB) showed a markedly different pattern. Effects of CCG-1423 and Lat B on gene expression correlated with literature studies of MKL knock-down. Gene sets involved in DNA synthesis and repair, G1/S transition, and apoptosis were modulated by CCG-1423. It also upregulated genes involved in endoplasmic reticulum stress. Targets of the known Rho target transcription factor family E2F and genes related to melanoma progression and metastasis were strongly suppressed by CCG-1423. These results confirm the ability of our compound to inhibit expression of numerous Rho/MKL-dependent genes and show effects on stress pathways as well. This suggests a novel approach to targeting aggressive cancers and metastasis. PMID:27600078

  10. Small-Molecule Inhibition of Rho/MKL/SRF Transcription in Prostate Cancer Cells: Modulation of Cell Cycle, ER Stress, and Metastasis Gene Networks.

    PubMed

    Evelyn, Chris R; Lisabeth, Erika M; Wade, Susan M; Haak, Andrew J; Johnson, Craig N; Lawlor, Elizabeth R; Neubig, Richard R

    2016-01-01

    Metastasis is the major cause of cancer deaths and control of gene transcription has emerged as a critical contributing factor. RhoA- and RhoC-induced gene transcription via the actin-regulated transcriptional co-activator megakaryocytic leukemia (MKL) and serum response factor (SRF) drive metastasis in breast cancer and melanoma. We recently identified a compound, CCG-1423, which blocks Rho/MKL/SRF-mediated transcription and inhibits PC-3 prostate cancer cell invasion. Here, we undertook a genome-wide expression study in PC-3 cells to explore the mechanism and function of this compound. There was significant overlap in the genes modulated by CCG-1423 and Latrunculin B (Lat B), which blocks the Rho/MKL/SRF pathway by preventing actin polymerization. In contrast, the general transcription inhibitor 5,6-dichloro-1-β-d-ribofuranosyl-1H-benzimidazole (DRB) showed a markedly different pattern. Effects of CCG-1423 and Lat B on gene expression correlated with literature studies of MKL knock-down. Gene sets involved in DNA synthesis and repair, G1/S transition, and apoptosis were modulated by CCG-1423. It also upregulated genes involved in endoplasmic reticulum stress. Targets of the known Rho target transcription factor family E2F and genes related to melanoma progression and metastasis were strongly suppressed by CCG-1423. These results confirm the ability of our compound to inhibit expression of numerous Rho/MKL-dependent genes and show effects on stress pathways as well. This suggests a novel approach to targeting aggressive cancers and metastasis. PMID:27600078

  11. Small-Molecule Inhibition of Rho/MKL/SRF Transcription in Prostate Cancer Cells: Modulation of Cell Cycle, ER Stress, and Metastasis Gene Networks

    PubMed Central

    Evelyn, Chris R.; Lisabeth, Erika M.; Wade, Susan M.; Haak, Andrew J.; Johnson, Craig N.; Lawlor, Elizabeth R.; Neubig, Richard R.

    2016-01-01

    Metastasis is the major cause of cancer deaths and control of gene transcription has emerged as a critical contributing factor. RhoA- and RhoC-induced gene transcription via the actin-regulated transcriptional co-activator megakaryocytic leukemia (MKL) and serum response factor (SRF) drive metastasis in breast cancer and melanoma. We recently identified a compound, CCG-1423, which blocks Rho/MKL/SRF-mediated transcription and inhibits PC-3 prostate cancer cell invasion. Here, we undertook a genome-wide expression study in PC-3 cells to explore the mechanism and function of this compound. There was significant overlap in the genes modulated by CCG-1423 and Latrunculin B (Lat B), which blocks the Rho/MKL/SRF pathway by preventing actin polymerization. In contrast, the general transcription inhibitor 5,6-dichloro-1-β-d-ribofuranosyl-1H-benzimidazole (DRB) showed a markedly different pattern. Effects of CCG-1423 and Lat B on gene expression correlated with literature studies of MKL knock-down. Gene sets involved in DNA synthesis and repair, G1/S transition, and apoptosis were modulated by CCG-1423. It also upregulated genes involved in endoplasmic reticulum stress. Targets of the known Rho target transcription factor family E2F and genes related to melanoma progression and metastasis were strongly suppressed by CCG-1423. These results confirm the ability of our compound to inhibit expression of numerous Rho/MKL-dependent genes and show effects on stress pathways as well. This suggests a novel approach to targeting aggressive cancers and metastasis.

  12. Media effects in modulating the conformational equilibrium of a model compound for tumor necrosis factor converting enzyme inhibition

    NASA Astrophysics Data System (ADS)

    Banchelli, Martina; Guardiani, Carlo; Sandberg, Robert B.; Menichetti, Stefano; Procacci, Piero; Caminati, Gabriella

    2015-07-01

    Small-molecule inhibitors of Tumor Necrosis Factor α Converting Enzyme (TACE) are a promising therapeutic tool for Rheumatoid Arthritis, Multiple Sclerosis and other autoimmune diseases. Here we report on an extensive chemical-physical analysis of the media effects in modulating the conformational landscape of MBET306, the common scaffold and a synthetic precursor of a family of recently discovered tartrate-based TACE inhibitors. The structural features of this molecule with potential pharmaceutical applications have been disclosed by interpreting extensive photophysical measurements in various solvents with the aid of enhanced sampling molecular dynamics simulations and time dependent density functional calculations. Using a combination of experimental and computational techniques, the paper provides a general protocol for studying the structure in solution of molecular systems characterized by the existence of conformational metastable states.

  13. ERBB activation modulates sensitivity to MEK1/2 inhibition in a subset of driver-negative melanoma

    PubMed Central

    Hutchinson, Katherine E.; Johnson, Douglas B.; Johnson, Adam S.; Sanchez, Violeta; Kuba, Maria; Lu, Pengcheng; Chen, Xi; Kelley, Mark C.; Wang, Qingguo; Zhao, Zhongming; Kris, Mark; Berger, Michael F.; Sosman, Jeffrey A.; Pao, William

    2015-01-01

    Melanomas are characterized by activating “driver” mutations in BRAF, NRAS, KIT, GNAQ, and GNA11. Resultant mitogen-activated protein kinase (MAPK) pathway signaling makes some melanomas susceptible to BRAF (BRAF V600 mutations), MEK1/2 (BRAF V600, L597, fusions; NRAS mutations), or other kinase inhibitors (KIT), respectively. Among driver-negative (“pan-negative”) patients, an unexplained heterogeneity of response to MEK1/2 inhibitors has been observed. Analysis of 16 pan-negative melanoma cell lines revealed that 8 (50%; termed Class I) are sensitive to the MEK1/2 inhibitor, trametinib, similar to BRAF V600E melanomas. A second set (termed Class II) display reduced trametinib sensitivity, paradoxical activation of MEK1/2 and basal activation of ERBBs 1, 2, and 3 (4 lines, 25%). In 3 of these lines, PI3K/AKT and MAPK pathway signaling is abrogated using the ERBB inhibitor, afatinib, and proliferation is even further reduced upon the addition of trametinib. A potential mechanism of ERBB activation in Class II melanomas is minimal expression of the ERK1/2 phosphatase, DUSP4, as ectopic restoration of DUSP4 attenuated ERBB signaling through potential modulation of the ERBB ligand, amphiregulin (AREG). Consistent with these data, immunohistochemical analysis of patient melanomas revealed a trend towards lower overall DUSP4 expression in pan-negative versus BRAF- and NRAS-mutant tumors. This study is the first to demonstrate that differential ERBB activity in pan-negative melanoma may modulate sensitivity to clinically-available MEK1/2 inhibitors and provides rationale for the use of ERBB inhibitors, potentially in combination with MEK1/2 inhibitors, in subsets of this disease. PMID:26084293

  14. 6-Gingerol inhibits Vibrio cholerae-induced proinflammatory cytokines in intestinal epithelial cells via modulation of NF-κB.

    PubMed

    Saha, Pallashri; Katarkar, Atul; Das, Bornita; Bhattacharyya, Aritra; Chaudhuri, Keya

    2016-09-01

    Context The effect of 6-gingerol (6G), the bioactive component of Zingiber officinale Roscoe (Zingiberaceae), in the reduction of Vibrio cholerae (Vibrionaceae)-induced inflammation has not yet been reported. Materials and methods Cell viability assay was performed to determine the working concentration of 6G. Elisa and RT-PCR were performed with Int 407 cells treated with 50 μM 6G and 100 multiplicity of infection (MOI) V. cholerae for 0, 2, 3, 3.5, 6 and 8 h to determine the concentration of IL-8, IL-6, IL-1α and IL-1β in both protein and RNA levels. Furthermore, the effect of 50 μM 6G on upstream MAP-kinases and NF-κB signalling pathways was evaluated at 0, 10, 15, 30, 60 and 90 min. Results The effective dose (ED50) value of 6G was found to be 50 μM as determined by cell viability assay. Pre-treatment with 50 μM 6G reduced V. cholerae infection-triggered levels of IL-8, IL-6, IL-1α and IL-1β by 3.2-fold in the protein level and two-fold in the RNA level at 3.5 h. The levels of MAP-kinases signalling molecules like p38 and ERK1/2 were also reduced by two- and three-fold, respectively, after 30 min of treatment. Additionally, there was an increase in phosphorylated IκBα and down-regulation of p65 resulting in down-regulation of NF-κB pathway. Conclusion Our results showed that 6G could modulate the anti-inflammatory responses triggered by V. cholerae-induced infection in intestinal epithelial cells by modulating NF-κB pathway. PMID:26987371

  15. Phospholipase A2 inhibits cisplatin-induced acute kidney injury by modulating regulatory T cells by the CD206 mannose receptor.

    PubMed

    Kim, Hyunseong; Lee, Hyojung; Lee, Gihyun; Jang, Hyunil; Kim, Sung-Su; Yoon, Heera; Kang, Geun-Hyung; Hwang, Deok-Sang; Kim, Sun Kwang; Chung, Hwan-Suck; Bae, Hyunsu

    2015-09-01

    Previously, we found that Foxp3-expressing CD4(+) regulatory T (Treg) cells attenuate cisplatin-induced acute kidney injury in mice and that bee venom and its constituent phospholipase A2 (PLA2) are capable of modulating Treg cells. Here we tested whether PLA2 could inhibit cisplatin-induced acute kidney injury. As a result of treatment with PLA2, the population of Treg cells was significantly increased, both in vivo and in vitro. PLA2-injected mice showed reduced levels of serum creatinine, blood urea nitrogen, renal tissue damage, and pro-inflammatory cytokine production upon cisplatin administration. These renoprotective effects were abolished by depletion of Treg cells. Furthermore, PLA2 bound to CD206 mannose receptors on dendritic cells, essential for the PLA2-mediated protective effects on renal dysfunction. Interestingly, PLA2 treatment increased the secretion of IL-10 in the kidney from normal mice. Foxp3(+)IL-10(+) cells and CD11c(+)IL-10(+) cells were increased by PLA2 treatment. The anticancer effects of repeated administrations of a low dose of cisplatin were not affected by PLA2 treatment in a tumor-bearing model. Thus, PLA2 may prevent inflammatory responses in cisplatin-induced acute kidney injury by modulating Treg cells and IL-10 through the CD206 mannose receptor.

  16. 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

  17. 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.

  18. Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

    PubMed Central

    Kuo, Han-Peng; Hsu, Shih-Chung; Li, Jhy-Wei; Tseng, Hsiu-Hsueh; Chuang, Tzu-Chao; Liu, Jah-Yao; Chen, Shih-Jung; Su, Muh-Hwan; Cheng, Yung-Chi; Chou, Wei-Yuan; Kao, Ming-Ching

    2013-01-01

    Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT), one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE) inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin) in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2. PMID:23662119

  19. Caffeine inhibits adipogenesis through modulation of mitotic clonal expansion and the AKT/GSK3 pathway in 3T3-L1 adipocytes.

    PubMed

    Kim, Ah-Reum; Yoon, Bo Kyung; Park, Hyounkyoung; Seok, Jo Woon; Choi, Hyeonjin; Yu, Jung Hwan; Choi, Yoonjeong; Song, Su Jin; Kim, Ara; Kim, Jae-Woo

    2016-02-01

    Caffeine has been proposed to have several beneficial effects on obesity and its related metabolic diseases; however, how caffeine affects adipocyte differentiation has not been elucidated. In this study, we demonstrated that caffeine suppressed 3T3-L1 adipocyte differentiation and inhibited the expression of CCAAT/enhancer binding protein (C/EBP)α and peroxisome proliferator-activated receptor (PPAR)γ, two main adipogenic transcription factors. Anti-adipogenic markers, such as preadipocyte secreted factor (Pref)-1 and Krüppel-like factor 2, remained to be expressed in the presence of caffeine. Furthermore, 3T3-L1 cells failed to undergo typical mitotic clonal expansion in the presence of caffeine. Investigation of hormonal signaling revealed that caffeine inhibited the activation of AKT and glycogen synthase kinase (GSK) 3 in a dose-dependent manner, but not extracellular signal-regulated kinase (ERK). Our data show that caffeine is an anti-adipogenic bioactive compound involved in the modulation of mitotic clonal expansion during adipocyte differentiation through the AKT/GSK3 pathway. [BMB Reports 2016; 49(2): 111-115].

  20. Human sputum cathepsin B degrades proteoglycan, is inhibited by alpha 2-macroglobulin and is modulated by neutrophil elastase cleavage of cathepsin B precursor and cystatin C.

    PubMed Central

    Buttle, D J; Abrahamson, M; Burnett, D; Mort, J S; Barrett, A J; Dando, P M; Hill, S L

    1991-01-01

    The high-Mr alkali-stable form of cathepsin B was purified from purulent human sputum. It was shown to solubilize proteoglycan monomer entrapped in polyacrylamide at a rate comparable with that of human lysosomal cathepsin B. Like the enzyme from lysosomes, sputum cathepsin B was bound by human alpha 2-macroglobulin, which inhibited its action on proteoglycan. Cystatin C in purulent sputum was shown to be the N-terminally truncated form generated by neutrophil elastase cleavage, and sputum cathepsin B was only weakly inhibited by recombinant cystatin C that had been cleaved by neutrophil elastase in vitro. Addition of neutrophil elastase to mucoid sputum led to a 5-fold increase in cathepsin B activity concomitant with a lowering in Mr of the cysteine proteinase from 40,000 to 37,000, i.e. the size of the active enzyme purified from purulent sputum. It is concluded that the high-Mr form of cathepsin B present in purulent sputum is a functional proteinase, unlike similar forms of the enzyme secreted by mammary gland in organ culture. The activity of cathepsin B in sputum is modulated by neutrophil elastase, by a combination of inhibitor inactivation and zymogen activation. Images Fig. 3. Fig. 4. Fig. 5. PMID:1710889

  1. Methylselenol, a selenium metabolite, modulates p53 pathway and inhibits the growth of colon cancer xenografts in Balb/c mice.

    PubMed

    Zeng, Huawei; Cheng, Wen-Hsing; Johnson, Luann K

    2013-05-01

    It is has been hypothesized that methylselenol is a critical selenium metabolite for anticancer activity in vivo. In this study, we used a protein array which contained 112 different antibodies known to be involved in the p53 pathway to investigate the molecular targets of methylselenol in human HCT116 colon cancer cells. The array analysis indicated that methylselenol exposure changed the expression of 11 protein targets related to the regulation of cell cycle and apoptosis. Subsequently, we confirmed these proteins with the Western blotting approach, and found that methylselenol increased the expression of GADD 153 and p21 but reduced the level of c-Myc, E2F1 and Phos p38 MAP kinase. Similar to our previous report on human HCT116 colon cancer cells, methylselenol also inhibited cell growth and led to an increase in G1 and G2 fractions with a concomitant drop in S-phase in mouse colon cancer MC26 cells. When the MC26 cells were transplanted to their immune-competent Balb/c mice, methylselenol-treated MC26 cells had significantly less tumor growth potential than that of untreated MC26 cells. Taken together, our data suggest that methylselenol modulates the expression of key genes related to cell cycle and apoptosis and inhibits colon cancer cell proliferation and tumor growth.

  2. Astragalin inhibits airway eotaxin-1 induction and epithelial apoptosis through modulating oxidative stress-responsive MAPK signaling

    PubMed Central

    2014-01-01

    Background Eotaxin proteins are a potential therapeutic target in treating the peribronchial eosinophilia associated with allergic airway diseases. Since inflammation is often associated with an increased generation of reactive oxygen species (ROS), oxidative stress is a mechanistically imperative factor in asthma. Astragalin (kaempferol-3-O-glucoside) is a flavonoid with anti-inflammatory activity and newly found in persimmon leaves and green tea seeds. This study elucidated that astragalin inhibited endotoxin-induced oxidative stress leading to eosinophilia and epithelial apoptosis in airways. Methods Airway epithelial BEAS-2B cells were exposed to lipopolysaccharide (LPS) in the absence and presence of 1–20 μM astragalin. Western blot and immunocytochemical analyses were conducted to determine induction of target proteins. Cell and nuclear staining was also performed for ROS production and epithelial apoptosis. Results When airway epithelial cells were exposed to 2 μg/ml LPS, astragalin nontoxic at ≤20 μM suppressed cellular induction of Toll-like receptor 4 (TLR4) and ROS production enhanced by LPS. Both LPS and H2O2 induced epithelial eotaxin-1 expression, which was blocked by astragalin. LPS activated and induced PLCγ1, PKCβ2, and NADPH oxidase subunits of p22phox and p47phox in epithelial cells and such activation and induction were demoted by astragalin or TLR4 inhibition antagonizing eotaxin-1 induction. H2O2-upregulated phosphorylation of JNK and p38 MAPK was dampened by adding astragalin to epithelial cells, while this compound enhanced epithelial activation of Akt and ERK. H2O2 and LPS promoted epithelial apoptosis concomitant with nuclear condensation or caspase-3 activation, which was blunted by astragalin. Conclusions Astragalin ameliorated oxidative stress-associated epithelial eosinophilia and apoptosis through disturbing TLR4-PKCβ2-NADPH oxidase-responsive signaling. Therefore, astragalin may be a potent agent antagonizing endotoxin

  3. Protein kinase B modulates the sensitivity of human neuroblastoma cells to insulin-like growth factor receptor inhibition.

    PubMed

    Guerreiro, Ana S; Boller, Danielle; Shalaby, Tarek; Grotzer, Michael A; Arcaro, Alexandre

    2006-12-01

    The potential of the novel insulin-like growth factor receptor (IGF-IR) inhibitor NVP-AEW541 as an antiproliferative agent in human neuroblastoma was investigated. Proliferation of a panel of neuroblastoma cell lines was inhibited by NVP-AEW541 with IC(50) values ranging from 0.15 to 5 microM. Experiments using an IGF-IR neutralizing antibody confirmed that the IGF-IR was essential to support growth of neuroblastoma cell lines. The expression levels of the IGF-IR in individual neuroblastoma cell lines did not correlate with the sensitivities to NVP-AEW541, while coexpression of the IGF-IR and the insulin receptor (IR) correlated with lower sensitivity to the inhibitor in some cell lines. Intriguingly, high levels of activation of Akt/protein kinase B (PKB) and phosphorylation of the ribosomal S6 protein were observed in neuroblastoma cell lines with decreased sensitivities to NVP-AEW541. Inhibition of Akt/PKB activity restored the sensitivity of neuroblastoma cells to the IGF-IR inhibitor. Transfection of neuroblastoma cells with activated Akt or ribosomal protein S6 kinase (S6K) decreased the sensitivity of the cells to NVP-AEW541. IGF-I-stimulated proliferation of neuroblastoma cell lines was completely blocked by NVP-AEW541, or by a combination of an inhibitor of phosphoinositide 3-kinase and rapamycin. In addition to its antiproliferative effects, NVP-AEW541 sensitized neuroblastoma cells to cisplatin-induced apoptosis. Together, our data demonstrate that NVP-AEW541 in combination with Akt/PKB inhibitors or chemotherapeutic agents may represent a novel approach to target human neuroblastoma cell proliferation.

  4. The Mycobacterium tuberculosis relBE toxin:antitoxin genes are stress-responsive modules that regulate growth through translation inhibition.

    PubMed

    Korch, Shaleen B; Malhotra, Vandana; Contreras, Heidi; Clark-Curtiss, Josephine E

    2015-11-01

    Toxin-antitoxin (TA) genes are ubiquitous among bacteria and are associated with persistence and dormancy. Following exposure to unfavorable environmental stimuli, several species (Escherichia coli, Staphylococcus aureus, Myxococcus xanthus) employ toxin proteins such as RelE and MazF to downregulate growth or initiate cell death. Mycobacterium tuberculosis possesses three Rel TA modules (Rel Mtb ): RelBE Mtb , RelFG Mtb and RelJK Mtb (Rv1246c-Rv1247c, Rv2865-Rv2866, and Rv3357-Rv3358, respectively), which inhibit mycobacterial growth when the toxin gene (relE, relG, relK) is expressed independently of the antitoxin gene (relB, relF, relJ). In the present study, we examined the in vivo mechanism of the RelE Mtb toxin protein, the impact of RelE Mtb on M. tuberculosis physiology and the environmental conditions that regulate all three rel Mtb modules. RelE Mtb negatively impacts growth and the structural integrity of the mycobacterial envelope, generating cells with aberrant forms that are prone to extensive aggregation. At a time coincident with growth defects, RelE Mtb mediates mRNA degradation in vivo resulting in significant changes to the proteome. We establish that rel Mtb modules are stress responsive, as all three operons are transcriptionally activated following mycobacterial exposure to oxidative stress or nitrogen-limiting growth environments. Here we present evidence that the rel Mtb toxin:antitoxin family is stress-responsive and, through the degradation of mRNA, the RelE Mtb toxin influences the growth, proteome and morphology of mycobacterial cells.

  5. The Mycobacterium tuberculosis relBE toxin:antitoxin genes are stress-responsive modules that regulate growth through translation inhibition.

    PubMed

    Korch, Shaleen B; Malhotra, Vandana; Contreras, Heidi; Clark-Curtiss, Josephine E

    2015-11-01

    Toxin-antitoxin (TA) genes are ubiquitous among bacteria and are associated with persistence and dormancy. Following exposure to unfavorable environmental stimuli, several species (Escherichia coli, Staphylococcus aureus, Myxococcus xanthus) employ toxin proteins such as RelE and MazF to downregulate growth or initiate cell death. Mycobacterium tuberculosis possesses three Rel TA modules (Rel Mtb ): RelBE Mtb , RelFG Mtb and RelJK Mtb (Rv1246c-Rv1247c, Rv2865-Rv2866, and Rv3357-Rv3358, respectively), which inhibit mycobacterial growth when the toxin gene (relE, relG, relK) is expressed independently of the antitoxin gene (relB, relF, relJ). In the present study, we examined the in vivo mechanism of the RelE Mtb toxin protein, the impact of RelE Mtb on M. tuberculosis physiology and the environmental conditions that regulate all three rel Mtb modules. RelE Mtb negatively impacts growth and the structural integrity of the mycobacterial envelope, generating cells with aberrant forms that are prone to extensive aggregation. At a time coincident with growth defects, RelE Mtb mediates mRNA degradation in vivo resulting in significant changes to the proteome. We establish that rel Mtb modules are stress responsive, as all three operons are transcriptionally activated following mycobacterial exposure to oxidative stress or nitrogen-limiting growth environments. Here we present evidence that the rel Mtb toxin:antitoxin family is stress-responsive and, through the degradation of mRNA, the RelE Mtb toxin influences the growth, proteome and morphology of mycobacterial cells. PMID:26502963

  6. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways

    PubMed Central

    Yan, Tingting; Zhao, Yan; Zhang, Xia; Lin, Xiaotong

    2016-01-01

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. Acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damage and cognitive dysfunction induced by chronic excessive alcohol consumption. In this study, the effect of astaxanthin, a marine bioactive compound, on acetaldehyde-induced cytotoxicity was investigated in SH-SY5Y cells. It was found that astaxanthin protected cells from apoptosis by ameliorating the effect of acetaldehyde on the expression of Bcl-2 family proteins, preventing the reduction of anti-apoptotic protein Bcl-2 and the increase of pro-apoptotic protein Bak induced by acetaldehyde. Further analyses showed that astaxanthin treatment inhibited acetaldehyde-induced reduction of the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB). Astaxanthin treatment also prevented acetaldehyde-induced increase of the level of activated p38 mitogen-activated protein kinase (MAPK) and decrease of the level of activated extracellular signal-regulated kinases (ERKs). Activation of Akt/CREB pathway promotes cell survival and is involved in the upregulation of Bcl-2 gene. P38MAPK plays a critical role in apoptotic events while ERKs mediates the inhibition of apoptosis. Thus, astaxanthin may inhibit acetaldehyde-induced apoptosis through promoting the activation of Akt/CREB and ERKs and blocking the activation of p38MAPK. In addition, astaxanthin treatment suppressed the oxidative stress induced by acetaldehyde and restored the antioxidative capacity of SH-SY5Y cells. Therefore, astaxanthin may protect cells against acetaldehyde-induced cytotoxicity through maintaining redox balance and modulating apoptotic and survival signals. The results suggest that astaxanthin treatment may be beneficial for preventing neurotoxicity associated with acetaldehyde and excessive alcohol consumption. PMID:26978376

  7. Inhibition of the betaine-GABA transporter (mGAT2/BGT-1) modulates spontaneous electrographic bursting in the medial entorhinal cortex (mEC).

    PubMed

    Smith, Misty D; Saunders, Gerald W; Clausen, Rasmus P; Frølund, Bente; Krogsgaard-Larsen, Povl; Larsson, Orla M; Schousboe, Arne; Wilcox, Karen S; White, H Steve

    2008-03-01

    Disruptions in GABAergic neurotransmission have been implicated in numerous CNS disorders, including epilepsy and neuropathic pain. Selective inhibition of neuronal and glial GABA transporter subtypes may offer unique therapeutic options for regaining balance between inhibitory and excitatory systems. The ability of two GABA transport inhibitors to modulate inhibitory tone via inhibition of mGAT1 (tiagabine) or mGAT2/BGT-1 (N-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]-4-(methylamino-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol), also known as EF1502) was evaluated using an in vitro model of spontaneous interictal-like bursting (SB). SBs were recorded extracellularly in combined mEC-HC horizontal brain slices (400 microm; 31+/-1 degrees C) obtained from KA-treated rats. Slice recordings demonstrated that EF1502 exhibited a concentration-dependent reduction in SB frequency. EF1502 significantly reduced SB rate to 32% of control at the 30 microM concentration, while reducing the area and duration of SB activity to 60% and 46% of control, respectively, at the 10 microM concentration. In contrast, the GAT1 selective inhibitor tiagabine (3, 10, and 30 microM) was unable to significantly reduce the frequency of SB activity in the mEC, despite significantly reducing both the duration (51% of control) and area (58% of control) of the SB at concentrations as low as 3 microM. The ability of EF1502, but not tiagabine, to inhibit SBs in the mEC suggests that this in vitro model of pharmacoresistant SB activity is useful to differentiate between novel anticonvulsants with similar mechanisms of action and suggests a therapeutic potential for non-GAT1 transport inhibitors. PMID:18262393

  8. All-trans-retinoic Acid Modulates the Plasticity and Inhibits the Motility of Breast Cancer Cells: ROLE OF NOTCH1 AND TRANSFORMING GROWTH FACTOR (TGFβ).

    PubMed

    Zanetti, Adriana; Affatato, Roberta; Centritto, Floriana; Fratelli, Maddalena; Kurosaki, Mami; Barzago, Maria Monica; Bolis, Marco; Terao, Mineko; Garattini, Enrico; Paroni, Gabriela

    2015-07-17

    All-trans-retinoic acid (ATRA) is a natural compound proposed for the treatment/chemoprevention of breast cancer. Increasing evidence indicates that aberrant regulation of epithelial-to-mesenchymal transition (EMT) is a determinant of the cancer cell invasive and metastatic behavior. The effects of ATRA on EMT are largely unknown. In HER2-positive SKBR3 and UACC812 cells, showing co-amplification of the ERBB2 and RARA genes, ATRA activates a RARα-dependent epithelial differentiation program. In SKBR3 cells, this causes the formation/reorganization of adherens and tight junctions. Epithelial differentiation and augmented cell-cell contacts underlie the anti-migratory action exerted by the retinoid in cells exposed to the EMT-inducing factors EGF and heregulin-β1. Down-regulation of NOTCH1, an emerging EMT modulator, is involved in the inhibition of motility by ATRA. Indeed, the retinoid blocks NOTCH1 up-regulation by EGF and/or heregulin-β1. Pharmacological inhibition of γ-secretase and NOTCH1 processing also abrogates SKBR3 cell migration. Stimulation of TGFβ contributes to the anti-migratory effect of ATRA. The retinoid switches TGFβ from an EMT-inducing and pro-migratory determinant to an anti-migratory mediator. Inhibition of the NOTCH1 pathway not only plays a role in the anti-migratory action of ATRA; it is relevant also for the anti-proliferative activity of the retinoid in HCC1599 breast cancer cells, which are addicted to NOTCH1 for growth/viability. This effect is enhanced by the combination of ATRA and the γ-secretase inhibitor N-(N-(3,5-difluorophenacetyl)-l-alanyl)-S-phenylglycine t-butyl ester, supporting the concept that the two compounds act at the transcriptional and post-translational levels along the NOTCH1 pathway. PMID:26018078

  9. All-trans-retinoic Acid Modulates the Plasticity and Inhibits the Motility of Breast Cancer Cells: ROLE OF NOTCH1 AND TRANSFORMING GROWTH FACTOR (TGFβ).

    PubMed

    Zanetti, Adriana; Affatato, Roberta; Centritto, Floriana; Fratelli, Maddalena; Kurosaki, Mami; Barzago, Maria Monica; Bolis, Marco; Terao, Mineko; Garattini, Enrico; Paroni, Gabriela

    2015-07-17

    All-trans-retinoic acid (ATRA) is a natural compound proposed for the treatment/chemoprevention of breast cancer. Increasing evidence indicates that aberrant regulation of epithelial-to-mesenchymal transition (EMT) is a determinant of the cancer cell invasive and metastatic behavior. The effects of ATRA on EMT are largely unknown. In HER2-positive SKBR3 and UACC812 cells, showing co-amplification of the ERBB2 and RARA genes, ATRA activates a RARα-dependent epithelial differentiation program. In SKBR3 cells, this causes the formation/reorganization of adherens and tight junctions. Epithelial differentiation and augmented cell-cell contacts underlie the anti-migratory action exerted by the retinoid in cells exposed to the EMT-inducing factors EGF and heregulin-β1. Down-regulation of NOTCH1, an emerging EMT modulator, is involved in the inhibition of motility by ATRA. Indeed, the retinoid blocks NOTCH1 up-regulation by EGF and/or heregulin-β1. Pharmacological inhibition of γ-secretase and NOTCH1 processing also abrogates SKBR3 cell migration. Stimulation of TGFβ contributes to the anti-migratory effect of ATRA. The retinoid switches TGFβ from an EMT-inducing and pro-migratory determinant to an anti-migratory mediator. Inhibition of the NOTCH1 pathway not only plays a role in the anti-migratory action of ATRA; it is relevant also for the anti-proliferative activity of the retinoid in HCC1599 breast cancer cells, which are addicted to NOTCH1 for growth/viability. This effect is enhanced by the combination of ATRA and the γ-secretase inhibitor N-(N-(3,5-difluorophenacetyl)-l-alanyl)-S-phenylglycine t-butyl ester, supporting the concept that the two compounds act at the transcriptional and post-translational levels along the NOTCH1 pathway.

  10. Combined inhibition of IL1, CXCR1/2, and TGFβ signaling pathways modulates in-vivo resistance to anti-VEGF treatment.

    PubMed

    Carbone, Carmine; Tamburrino, Anna; Piro, Geny; Boschi, Federico; Cataldo, Ivana; Zanotto, Marco; Mina, Maria M; Zanini, Silvia; Sbarbati, Andrea; Scarpa, Aldo; Tortora, Giampaolo; Melisi, Davide

    2016-01-01

    Resistance of tumors to antiangiogenic therapies is becoming increasingly relevant. We recently identified interleukin-1 (IL1), CXC receptors (CXCR)1/2 ligands, and transforming growth factor β (TGFβ) among the proinflammatory factors that were expressed at higher levels in murine models resistant to the antivascular endothelial growth factor (anti-VEGF) antibody bevacizumab. Here, we hypothesized that the combined inhibition of these proinflammatory signaling pathways might reverse this anti-VEGF resistance. Bevacizumab-resistant FGBR pancreatic cancer cells were treated in vitro with bevacizumab, the recombinant human IL1 receptor antagonist anakinra, the monoclonal antibody against TGFβ receptor type II TR1, and a novel recombinant antibody binding CXCR1/2 ligands. The FGBR cells treated with these agents in combination had significantly higher levels of E-cadherin and lower levels of vimentin, IL6, phosphorylated p65, and SMAD2, and showed significantly lower migration rates than did their controls treated with the same agents without bevacizumab or with a single agent bevacizumab as a control. Consistently, the combination of these agents with bevacizumab reduced the FGBR tumor burden and significantly prolonged mice survival compared with bevacizumab in monotherapy. Tumors from mice receiving the combination treatment showed significantly lower expression of IL6 and phosphorylated SMAD2, higher expression of E-cadherin and lower levels of vimentin, and a significantly lower infiltration by CD11b cells compared with bevacizumab-treated controls. This study suggests that inhibition of IL1, CXCR1/2, and TGFβ signaling pathways is a potential therapeutic approach to modulate the acquired resistance to anti-VEGF treatment by reversing epithelial-mesenchymal transition and inhibiting CD11b proangiogenic myeloid cells' tumor infiltration.

  11. The effect of a platelet cholesterol modulation on the acetylsalicylic acid-mediated blood platelet inhibition in hypercholesterolemic patients.

    PubMed

    Luzak, Boguslawa; Boncler, Magdalena; Rywaniak, Joanna; Wilk, Radoslaw; Stanczyk, Lidia; Czyz, Malgorzata; Rysz, Jacek; Watala, Cezary

    2011-05-11

    Aspirin (acetylsalicylic acid, ASA) is widely used in the prevention of cardiovascular disease, but its beneficial effects may be restrained in some individuals, where the reduced ability of ASA to protect against arterial thrombotic events is observed. We analyzed the influence of the treatment with atorvastatin (10mg/day) on the platelet sensitivity to ASA monitored under in vitro conditions in hypercholesterolemic patients. The associations between plasma or platelet cholesterol parameters and the ASA-mediated inhibition of platelet reactivity or the extent of platelet protein acetylation by ASA were estimated in the patients treated with atorvastatin for 1, 3, or 6 months. Out of 27 patients, in 17 individuals platelets appeared significantly more sensitive to 50 μM ASA in arachidonic acid- or collagen-induced whole blood aggregation following 1 month atorvastatin therapy (inhibition by 60.9 ± 5.6% vs. 48.8 ± 5.4%, P<0.05 for 0.5mM arachidonic acid, 40.8 ± 2.9% vs. 27.0 ± 4.1%, P<0.05 for 1 μg/ml collagen), and this effect lasted for 3 and 6 months, remaining in a weak, although significant, relation to the reduction of platelet cholesterol content (R(S)=-0.277, P<0.002 for arachidonic acid, R(S)=-0.197, P<0.02 for collagen). It was, however, not dependent upon either antiplatelet action or plasma lipid-lowering activity of atorvastatin. In addition, in about 50% of patients, we noticed that ASA (50 μM) significantly and time-dependently diminished thromboxane B(2) concentration in atorvastatin-treated patients. The ASA-induced acetylation of platelet proteins significantly increased in the course of atorvastatin therapy and was associated with reduced platelet cholesterol (R(S)=-0.598, P<0.0001). In conclusion, statin therapy may improve platelet sensitivity to ASA in some hypercholesterolemic patients. This effect may extend beyond the action of atorvastatin as merely a lipid-lowering agent. The mechanisms of resistance of some patients to such a

  12. Galactosylation of IgG1 modulates FcγRIIB-mediated inhibition of murine autoimmune hemolytic anemia.

    PubMed

    Yamada, Kazunori; Ito, Kiyoaki; Furukawa, Jun-Ichi; Nakata, Junichiro; Alvarez, Montserrat; Verbeek, J Sjef; Shinohara, Yasuro; Izui, Shozo

    2013-12-01

    Murine immune effector cells express three different stimulatory FcγRs (FcγRI, FcγRIII and FcγRIV) and one inhibitory receptor, FcγRIIB. Competitive engagement of stimulatory and inhibitory FcγRs has been shown to be critical for the development of immune complex-mediated inflammatory disorders. Because of the previous demonstration that FcγRIIB was unable to inhibit FcγRIII-mediated autoimmune hemolytic anemia induced by 105-2H IgG1 anti-RBC mAb, we reevaluated the regulatory role of FcγRIIB on the development of anemia using two additional IgG1 anti-RBC mAbs (34-3C and 3H5G1) and different 34-3C IgG subclass-switch variants. We were able to induce a more severe anemia in FcγRIIB-deficient mice than in FcγRIIB-sufficient mice after injection of 34-3C and 3H5G1 IgG1, but not 105-2H IgG1. Structural analysis of N-linked oligosaccharides attached to the CH2 domain revealed that 105-2H was poorly galactosylated as compared with the other mAbs, while the extent of sialylation was comparable between all mAbs. In addition, we observed that a more galactosylated 105-2H variant provoked more severe anemia in FcγRIIB-deficient mice than FcγRIIB-sufficient mice. In contrast, the development of anemia induced by three non-IgG1 subclass variants of the 34-3C mAb was not down-regulated by FcγRIIB, although they were more galactosylated than its IgG1 variant. These data indicate that FcγRIIB-mediated inhibition of autoimmune hemolytic anemia is restricted to the IgG1 subclass and that galactosylation, but not sialylation, of IgG1 (but not other IgG subclasses) is critical for the interaction with FcγR, thereby determining the pathogenic potential of IgG1 autoantibodies.

  13. Nicotine enhances inhibition of mouse vagal motor neurons by modulating excitability of premotor GABAergic neurons in the nucleus tractus solitarii

    PubMed Central

    Xu, Hong; Boychuk, Jeffery A.; Boychuk, Carie R.; Uteshev, Victor V.

    2014-01-01

    The caudal nucleus of the solitary tract (NTS) serves as the site of the first synapse for visceral sensory inputs to the central nervous system. The NTS sends functional projections to multiple brain nuclei, with gastric-related projections primarily targeting the dorsal motor nucleus of the vagus (DMV). Previous studies have demonstrated that the majority of caudal NTS neurons that project to the DMV respond robustly to nicotine and express nicotinic acetylcholine receptors (nAChRs). However, the cytochemical identity and relationship with specific viscera of DMV-projecting, nicotine-responsive caudal NTS neurons have not been determined. The present study used transgenic mice that express enhanced green fluorescent protein (EGFP) under a GAD67 promoter in a subset of GABAergic neurons, in vivo retrograde pseudorabies viral labeling to identify gastric-related vagal complex neurons, and patch-clamp electrophysiology in acute brain stem slices to test the hypothesis that gastric-related and GABAergic inhibitory synaptic input to the DMV from the caudal NTS is under a robust modulatory control by nAChRs. Our results suggest that activation of nAChRs in the caudal NTS, but not DMV, potentiates GABAergic, but not glutamatergic, input to the DMV. Gastric-related caudal NTS and DMV neurons are directly involved in this nicotine-sensitive circuitry. Understanding the central patterns of nicotinic modulation of visceral sensory-motor circuitry may help develop therapeutic interventions to restore autonomic homeostasis in patients with autonomic impairments. PMID:25429117

  14. Oleanolic acid acetate inhibits rheumatoid arthritis by modulating T cell immune responses and matrix-degrading enzymes.

    PubMed

    Choi, Jin Kyeong; Kim, Sung-Wan; Kim, Duk-Sil; Lee, Jong Yeong; Lee, Soyoung; Oh, Hyun-Mee; Ha, Yeong Su; Yoo, Jeongsoo; Park, Pil-Hoon; Shin, Tae-Yong; Kwon, Taeg Kyu; Rho, Mun-Chual; Kim, Sang-Hyun

    2016-01-01

    Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with a combination of synovium joint inflammation, synovium hyperplasia, and destruction of cartilage and bone. Oleanolic acid acetate (OAA), a compound isolated from Vigna angularis, has been known to possess pharmacological activities, including anti-inflammation and anti-bone destruction. In this study, we investigated the effects of OAA on RA and the underlying mechanisms of action by using a type-II collagen-induced arthritis (CIA) mouse model and tumor necrosis factor (TNF)-α-stimulated RA synovial fibroblasts. Oral administration of OAA decreased the clinical arthritis symptoms, paw thickness, histologic and radiologic changes, and serum total and anti-type II collagen IgG, IgG1, and IgG2a levels. OAA administration reduced Th1/Th17 phenotype CD4(+) T lymphocyte expansions and inflammatory cytokine productions in T cell activated draining lymph nodes and spleen. OAA reduced the expression and production of inflammatory mediators, such as cytokines and matrix metalloproteinase (MMP)-1/3, in the ankle joint tissue and RA synovial fibroblasts by down-regulating Akt, mitogen-activated protein kinases, and nuclear factor-κB. Our results clearly support that OAA plays a therapeutic role in RA pathogenesis by modulating helper T cell immune responses and matrix-degrading enzymes. The immunosuppressive effects of OAA were comparable to dexamethasone and ketoprofen. We provide evidences that OAA could be a potential therapeutic candidate for RA. PMID:26570984

  15. Oleanolic acid acetate inhibits rheumatoid arthritis by modulating T cell immune responses and matrix-degrading enzymes.

    PubMed

    Choi, Jin Kyeong; Kim, Sung-Wan; Kim, Duk-Sil; Lee, Jong Yeong; Lee, Soyoung; Oh, Hyun-Mee; Ha, Yeong Su; Yoo, Jeongsoo; Park, Pil-Hoon; Shin, Tae-Yong; Kwon, Taeg Kyu; Rho, Mun-Chual; Kim, Sang-Hyun

    2016-01-01

    Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with a combination of synovium joint inflammation, synovium hyperplasia, and destruction of cartilage and bone. Oleanolic acid acetate (OAA), a compound isolated from Vigna angularis, has been known to possess pharmacological activities, including anti-inflammation and anti-bone destruction. In this study, we investigated the effects of OAA on RA and the underlying mechanisms of action by using a type-II collagen-induced arthritis (CIA) mouse model and tumor necrosis factor (TNF)-α-stimulated RA synovial fibroblasts. Oral administration of OAA decreased the clinical arthritis symptoms, paw thickness, histologic and radiologic changes, and serum total and anti-type II collagen IgG, IgG1, and IgG2a levels. OAA administration reduced Th1/Th17 phenotype CD4(+) T lymphocyte expansions and inflammatory cytokine productions in T cell activated draining lymph nodes and spleen. OAA reduced the expression and production of inflammatory mediators, such as cytokines and matrix metalloproteinase (MMP)-1/3, in the ankle joint tissue and RA synovial fibroblasts by down-regulating Akt, mitogen-activated protein kinases, and nuclear factor-κB. Our results clearly support that OAA plays a therapeutic role in RA pathogenesis by modulating helper T cell immune responses and matrix-degrading enzymes. The immunosuppressive effects of OAA were comparable to dexamethasone and ketoprofen. We provide evidences that OAA could be a potential therapeutic candidate for RA.

  16. MiR-146a modulates macrophage polarization by inhibiting Notch1 pathway in RAW264.7 macrophages.

    PubMed

    Huang, Cheng; Liu, Xue-jiao; QunZhou; Xie, Juan; Ma, Tao-tao; Meng, Xiao-ming; Li, Jun

    2016-03-01

    Macrophages are heterogeneous and plastic cells which are able to undergo dynamic transition between M1 and M2 polarized phenotypes in response to the microenvironment signals. However, the underlying molecular mechanisms of macrophage polarization are still obscure. In the current study, it was revealed that miR-146a might play a pivotal role in macrophage polarization. As our results indicated, miR-146a was highly expressed in M2 macrophages rather than M1 macrophages. Over-expression of miR-146a resulted in significantly decreased production of pro-inflammatory cytokines including iNOS and TNF-α in M1 macrophages, while increased production of M2 marker genes such as Arg1 and CD206 in M2 macrophages. In contrast, knockdown of miR-146a promoted M1 macrophage polarization but diminished M2 macrophage polarization. Mechanistically, it was revealed that miR-146a modulated macrophage polarization by targeting Notch1. Of note, PPARγ was responsible as another target for miR-146a-mediated macrophage polarization. Taken together, it was suggested that miR-146a might serve as a molecular regulator in macrophage polarization and is a potential therapeutic target for inflammatory diseases.

  17. Fisetin Modulates Antioxidant Enzymes and Inflammatory Factors to Inhibit Aflatoxin-B1 Induced Hepatocellular Carcinoma in Rats

    PubMed Central

    Maurya, Brajesh Kumar; Trigun, Surendra Kumar

    2016-01-01

    Fisetin, a known antioxidant, has been found to be cytotoxic against certain cell lines. However, the mechanism by which it inhibits tumor growth in vivo remains unexplored. Recently, we have demonstrated that Aflatoxin-B1 (AFB1) induced hepatocarcinogenesis is associated with activation of oxidative stress-inflammatory pathway in rat liver. The present paper describes the effect of in vivo treatment with 20 mg/kg b.w. Fisetin on antioxidant enzymes vis-a-vis oxidative stress level and on the profile of certain proinflammatory cytokines in the hepatocellular carcinoma (HCC) induced by two doses of 1 mg/kg b.w. AFB1 i.p. in rats. The reduced levels of most of the antioxidant enzymes, coinciding with the enhanced level of reactive oxygen species in the HCC liver, were observed to regain their normal profiles due to Fisetin treatment. Also, Fisetin treatment could normalize the enhanced expression of TNFα and IL1α, the two proinflammatory cytokines, reported to be involved in HCC pathogenesis. These observations were consistent with the regression of neoplastic lesion and declined GST-pi (placental type glutathione-S-transferase) level, a HCC marker, in the liver of the Fisetin treated HCC rats. The findings suggest that Fisetin attenuates oxidative stress-inflammatory pathway of AFB1 induced hepatocarcinogenesis. PMID:26682000

  18. TCF7L1 Modulates Colorectal Cancer Growth by Inhibiting Expression of the Tumor-Suppressor Gene EPHB3

    PubMed Central

    Murphy, Matthew; Chatterjee, Sujash S.; Jain, Sidharth; Katari, Manpreet; DasGupta, Ramanuj

    2016-01-01

    Dysregulation of the Wnt pathway leading to accumulation of β-catenin (CTNNB1) is a hallmark of colorectal cancer (CRC). Nuclear CTNNB1 acts as a transcriptional coactivator with TCF/LEF transcription factors, promoting expression of a broad set of target genes, some of which promote tumor growth. However, it remains poorly understood how CTNNB1 interacts with different transcription factors in different contexts to promote different outcomes. While some CTNNB1 target genes are oncogenic, others regulate differentiation. Here, we found that TCF7L1, a Wnt pathway repressor, buffers CTNNB1/TCF target gene expression to promote CRC growth. Loss of TCF7L1 impaired growth and colony formation of HCT116 CRC cells and reduced tumor growth in a mouse xenograft model. We identified a group of CTNNB1/TCF target genes that are activated in the absence of TCF7L1, including EPHB3, a marker of Paneth cell differentiation that has also been implicated as a tumor suppressor in CRC. Knockdown of EPHB3 partially restores growth and normal cell cycle progression of TCF7L1-Null cells. These findings suggest that while CTNNB1 accumulation is critical for CRC progression, activation of specific Wnt target genes in certain contexts may in fact inhibit tumor growth. PMID:27333864

  19. TCF7L1 Modulates Colorectal Cancer Growth by Inhibiting Expression of the Tumor-Suppressor Gene EPHB3.

    PubMed

    Murphy, Matthew; Chatterjee, Sujash S; Jain, Sidharth; Katari, Manpreet; DasGupta, Ramanuj

    2016-01-01

    Dysregulation of the Wnt pathway leading to accumulation of β-catenin (CTNNB1) is a hallmark of colorectal cancer (CRC). Nuclear CTNNB1 acts as a transcriptional coactivator with TCF/LEF transcription factors, promoting expression of a broad set of target genes, some of which promote tumor growth. However, it remains poorly understood how CTNNB1 interacts with different transcription factors in different contexts to promote different outcomes. While some CTNNB1 target genes are oncogenic, others regulate differentiation. Here, we found that TCF7L1, a Wnt pathway repressor, buffers CTNNB1/TCF target gene expression to promote CRC growth. Loss of TCF7L1 impaired growth and colony formation of HCT116 CRC cells and reduced tumor growth in a mouse xenograft model. We identified a group of CTNNB1/TCF target genes that are activated in the absence of TCF7L1, including EPHB3, a marker of Paneth cell differentiation that has also been implicated as a tumor suppressor in CRC. Knockdown of EPHB3 partially restores growth and normal cell cycle progression of TCF7L1-Null cells. These findings suggest that while CTNNB1 accumulation is critical for CRC progression, activation of specific Wnt target genes in certain contexts may in fact inhibit tumor growth. PMID:27333864

  20. Salvianolic Acid B Inhibits Aβ Generation by Modulating BACE1 Activity in SH-SY5Y-APPsw Cells

    PubMed Central

    Tang, Ying; Huang, Dan; Zhang, Mei-Hua; Zhang, Wen-Sheng; Tang, Yu-Xin; Shi, Zheng-Xiang; Deng, Li; Zhou, Dai-Han; Lu, Xin-Yi

    2016-01-01

    Alzheimer’s disease (AD) is a neurodegenerative disease in humans. The accumulation of amyloid-β (Aβ) plays a critical role in the pathogenesis of AD. Previous studies indicated that Salvianolic acid B (SalB) could ameliorate Aβ-induced memory impairment. However, whether SalB could influence the generation of Aβ is unclear. Here, we show that SalB (25, 50, or 100 µM) reduces the generation of Aβ40 and Aβ42 in culture media by decreasing the protein expressions of BACE1 and sAPPβ in SH-SY5Y-APPsw cells. Meanwhile, SalB increases the levels of ADAM10 and sAPPα in the cells. However, SalB has no impact on the protein expressions of APP and PS1. Moreover, SalB attenuates oxidative stress and inhibits the activity of GSK3β, which might be related to the suppression of BACE1 expression and amyloidogenesis. Our study suggests that SalB is a promising therapeutic agent for AD by targeting Aβ generation. PMID:27258307

  1. The Natural Product Resveratrol Inhibits Yeast Cell Separation by Extensively Modulating the Transcriptional Landscape and Reprogramming the Intracellular Metabolome

    PubMed Central

    Shen, Yan; Wang, Yang; Li, Jing; Lv, Hong; Huo, Keke

    2016-01-01

    An increasing number of studies have shown that the promising compound resveratrol treats multiple diseases, such as cancer and aging; however, the resveratrol mode-of-action (MoA) remains largely unknown. Here, by virtue of multiple omics approaches, we adopted fission yeast as a model system with the goal of dissecting the common MoA of the anti-proliferative activity of resveratrol. We found that the anti-proliferative activity of resveratrol is mainly due to its unique role of inhibiting the separation of sister cells, similar phenotype with the C2H2 zinc finger transcription factor Ace2 knock-out strain. Microarray analysis shown that resveratrol has extensive impact on the fission yeast transcription levels. Among the changed gene’s list, 40% of up-regulated genes are Core Environmental Stress Responses genes, and 57% of the down-regulated genes are periodically expressed. Moreover, resveratrol leverages the metabolome, which unbalances the intracellular pool sizes of several classes of amino acids, nucleosides, sugars and lipids, thus reflecting the remodulated metabolic networks. The complexity of the resveratrol MoA displayed in previous reports and our work demonstrates that multiple omics approaches must be applied together to obtain a complete picture of resveratrol’s anti-proliferative function. PMID:26950930

  2. Fisetin Modulates Antioxidant Enzymes and Inflammatory Factors to Inhibit Aflatoxin-B1 Induced Hepatocellular Carcinoma in Rats.

    PubMed

    Maurya, Brajesh Kumar; Trigun, Surendra Kumar

    2016-01-01

    Fisetin, a known antioxidant, has been found to be cytotoxic against certain cell lines. However, the mechanism by which it inhibits tumor growth in vivo remains unexplored. Recently, we have demonstrated that Aflatoxin-B1 (AFB1) induced hepatocarcinogenesis is associated with activation of oxidative stress-inflammatory pathway in rat liver. The present paper describes the effect of in vivo treatment with 20 mg/kg b.w. Fisetin on antioxidant enzymes vis-a-vis oxidative stress level and on the profile of certain proinflammatory cytokines in the hepatocellular carcinoma (HCC) induced by two doses of 1 mg/kg b.w. AFB1 i.p. in rats. The reduced levels of most of the antioxidant enzymes, coinciding with the enhanced level of reactive oxygen species in the HCC liver, were observed to regain their normal profiles due to Fisetin treatment. Also, Fisetin treatment could normalize the enhanced expression of TNFα and IL1α, the two proinflammatory cytokines, reported to be involved in HCC pathogenesis. These observations were consistent with the regression of neoplastic lesion and declined GST-pi (placental type glutathione-S-transferase) level, a HCC marker, in the liver of the Fisetin treated HCC rats. The findings suggest that Fisetin attenuates oxidative stress-inflammatory pathway of AFB1 induced hepatocarcinogenesis.

  3. Selective oestrogen receptor modulators lasofoxifene and bazedoxifene inhibit joint inflammation and osteoporosis in ovariectomised mice with collagen-induced arthritis

    PubMed Central

    Bernardi, Angelina I.; Stubelius, Alexandra; Nurkkala-Karlsson, Merja; Ohlsson, Claes; Carlsten, Hans; Islander, Ulrika

    2016-01-01

    Objective. RA predominantly affects post-menopausal women and is strongly associated with development of generalised osteoporosis. To find treatments that target both joint manifestations and osteoporosis in RA is desirable. The third generation of selective oestrogen receptor modulators (SERMs) [lasofoxifene (LAS) and bazedoxifene (BZA)] are new treatment options for post-menopausal osteoporosis. The aim of this study was to investigate the effects of LAS and BZA on arthritic disease and inflammation-associated bone loss using CIA in mice. Methods. Female DBA/1 mice were ovariectomised and subjected to CIA as a model of post-menopausal RA. Mice received treatment with LAS, BZA, 17β-estradiol (E2) as reference or vehicle. Arthritis development was assessed and BMD was determined by peripheral quantitative CT of the femurs. Serologic markers of inflammation and cartilage destruction were analysed. Immune cells in lymph nodes were studied by flow cytometry. Results. LAS and BZA reduced the clinical severity of arthritis as well as the grade of histologic synovitis and erosions on cartilage and bone. Moreover, SERMs protected against generalised bone loss in CIA by increasing trabecular BMD. Both SERMs decreased serum marker of cartilage destruction and LAS reduced serum IL-6 levels. SERMs did not alter Th17 cells in lymph nodes as E2 did. Conclusion. The anti-osteoporotic drugs LAS and BZA were found to be potent inhibitors of joint inflammation and bone destruction in experimental arthritis. This study provides new important knowledge regarding the treatment regimen of post-menopausal women with RA who suffer from increased risk for osteoporosis. PMID:26424839

  4. Allergy-Protective Arabinogalactan Modulates Human Dendritic Cells via C-Type Lectins and Inhibition of NF-κB.

    PubMed

    Peters, Marcus; Guidato, Patrick M; Peters, Karin; Megger, Dominik A; Sitek, Barbara; Classen, Birgit; Heise, Esther M; Bufe, Albrecht

    2016-02-15

    Arabinogalactan (AG) isolated from dust of a traditional farm prevents disease in murine models of allergy. However, it is unclear whether this polysaccharide has immune regulatory properties in humans. The aim of this study was to test the influence of AG on the immune-stimulating properties of human dendritic cells (DCs). Moreover, we sought to identify the receptor to which AG binds. AG was produced from plant callus tissue under sterile conditions to avoid the influence of pathogen-associated molecular patterns in subsequent experiments. The influence of AG on the human immune system was investigated by analyzing its impact on monocyte-derived DCs. To analyze whether the T cell stimulatory capacity of AG-stimulated DCs is altered, an MLR with naive Th cells was performed. We revealed that AG reduced T cell proliferation in a human MLR. In the search for a molecular mechanism, we found that AG binds to the immune modulatory receptors DC-specific ICAM-3 -: grabbing non integrin (DC-SIGN) and macrophage mannose receptor 1 (MMR-1). Stimulation of these receptors with AG simultaneously with TLR4 stimulation with LPS increased the expression of the E3 ubiquitin-protein ligase tripartite motif -: containing protein 21 and decreased the phosphorylation of NF-κB p65 in DCs. This led to a reduced activation profile with reduced costimulatory molecules and proinflammatory cytokine production. Blocking of MMR-1 or DC-SIGN with neutralizing Abs partially inhibits this effect. We conclude that AG dampens the activation of human DCs by LPS via binding to DC-SIGN and MMR-1, leading to attenuated TLR signaling. This results in a reduced T cell activation capacity of DCs. PMID:26746190

  5. A BMP7 Variant Inhibits Tumor Angiogenesis In Vitro and In Vivo through Direct Modulation of Endothelial Cell Biology

    PubMed Central

    Pallini, Roberto; Vakana, Eliza; Wyss, Lisa; Blosser, Wayne; Ricci-Vitiani, Lucia; D’Alessandris, Quintino Giorgio; Morgante, Liliana; Giannetti, Stefano; Maria Larocca, Luigi; Todaro, Matilde; Benfante, Antonina; Colorito, Maria Luisa; Stassi, Giorgio; De Maria, Ruggero; Rowlinson, Scott; Stancato, Louis

    2015-01-01

    Bone morphogenetic proteins (BMPs), members of the TGF-β superfamily, have numerous biological activities including control of growth, differentiation, and vascular development. Using an in vitro co-culture endothelial cord formation assay, we investigated the role of a BMP7 variant (BMP7v) in VEGF, bFGF, and tumor-driven angiogenesis. BMP7v treatment led to disruption of neo-endothelial cord formation and regression of existing VEGF and bFGF cords in vitro. Using a series of tumor cell models capable of driving angiogenesis in vitro, BMP7v treatment completely blocked cord formation. Pre-treatment of endothelial cells with BMP7v significantly reduced their cord forming ability, indicating a direct effect on endothelial cell function. BMP7v activated the canonical SMAD signaling pathway in endothelial cells but targeted gene knockdown using shRNA directed against SMAD4 suggests this pathway is not required to mediate the anti-angiogenic effect. In contrast to SMAD activation, BMP7v selectively decreased ERK and AKT activation, significantly decreased endothelial cell migration and down-regulated expression of critical RTKs involved in VEGF and FGF angiogenic signaling, VEGFR2 and FGFR1 respectively. Importantly, in an in vivo angiogenic plug assay that serves as a measurement of angiogenesis, BMP7v significantly decreased hemoglobin content indicating inhibition of neoangiogenesis. In addition, BMP7v significantly decreased angiogenesis in glioblastoma stem-like cell (GSLC) Matrigel plugs and significantly impaired in vivo growth of a GSLC xenograft with a concomitant reduction in microvessel density. These data support BMP7v as a potent anti-angiogenic molecule that is effective in the context of tumor angiogenesis. PMID:25919028

  6. [Modulation of S-1 conformation and inhibition of the skeletal muscle S-1-ATPase by calponin of the mussel].

    PubMed

    Sirenko, V V; Simonian, A O; Dobrzhanskaia, A V; Shelud'ko, N S; Borovikov, Iu S

    2014-01-01

    A novel 40 kDa protein has been detected in native thin filaments from catch muscles of the mussel Crenomytilus grayanus. In this study, using skeletal muscle actin and S-1, we investigated the effects of the mussel 40-kDa actin-binding protein on the acto · S-1 ATPase activity. On increasing the 40-kDa actin-binding protein (CaP-40) concentration, the actin-activated ATPase activity decreased, and was inhibited 80% at a CaP-40 to actin ratio of 0.5. Polarized fluorimetry technique and glycerinated muscle fibers were used to study effects of CaP-40 on the orientation and mobility of fluorescent label 1.5-IAEDANS specifically bound to CyS-707 of myosin subfragment-1 in the absence of nucleotide, and in the presence of MgADP or MgATP. We have concluded that CaP-40 binding to actin affects the strong binding of myosin to actin but has no effect on the weak binding. Thus, the influence of the CaP-40 on the formation of strong actomyosin binding forms A · M and A · M · ADP manifests itself by a decrease in the relative content of myosin cross-bridges strongly bound with actin, which probably results in a decrease in the relative content of "switch on" actin monomers in thin filaments. This suggests that, as calponin CaP-40 selects its target the phase of strong actomyosin binding binding which preceded by a phase generating power stroke.

  7. HDAC I inhibition in the dorsal and ventral hippocampus differentially modulates predator-odor fear learning and generalization

    PubMed Central

    Yuan, Robin K.; Hebert, Jenna C.; Thomas, Arthur S.; Wann, Ellen G.; Muzzio, Isabel A.

    2015-01-01

    Although predator odors are ethologically relevant stimuli for rodents, the molecular pathways and contribution of some brain regions involved in predator odor conditioning remain elusive. Inhibition of histone deacetylases (HDACs) in the dorsal hippocampus has been shown to enhance shock-induced contextual fear learning, but it is unknown if HDACs have differential effects along the dorso-ventral hippocampal axis during predator odor fear learning. We injected MS-275, a class I HDAC inhibitor, bilaterally in the dorsal or ventral hippocampus of mice and found that it had no effects on innate anxiety in either region. We then assessed the effects of MS-275 at different stages of fear learning along the longitudinal hippocampal axis. Animals were injected with MS-275 or vehicle after context pre-exposure (pre-conditioning injections), when a representation of the context is first formed, or after exposure to coyote urine (post-conditioning injections), when the context becomes associated with predator odor. When MS-275 was administered after context pre-exposure, dorsally injected animals showed enhanced fear in the training context but were able to discriminate it from a neutral environment. Conversely, ventrally injected animals did not display enhanced learning in the training context but generalized the fear response to a neutral context. However, when MS-275 was administered after conditioning, there were no differences between the MS-275 and vehicle control groups in either the dorsal or ventral hippocampus. Surprisingly, all groups displayed generalization to a neutral context, suggesting that predator odor exposure followed by a mild stressor such as restraint leads to fear generalization. These results may elucidate distinct functions of the dorsal and ventral hippocampus in predator odor-induced fear conditioning as well as some of the molecular mechanisms underlying fear generalization. PMID:26441495

  8. Environmental estrogens inhibit growth of rainbow trout (Oncorhynchus mykiss) by modulating the growth hormone-insulin-like growth factor system.

    PubMed

    Hanson, Andrea M; Kittilson, Jeffrey D; Martin, Lincoln E; Sheridan, Mark A

    2014-01-15

    Although environmental estrogens (EE) have been found to disrupt a wide variety of developmental and reproductive processes in vertebrates, there is a paucity of information concerning their effects on organismal growth, particularly postembryonic growth. In this study, we exposed juvenile rainbow trout (Oncorhynchus mykiss) to 17β-estradiol (E2) β-sitosterol (βS), or 4-n-nonylphenol (NP) to assess the effects of EE on overall organismal growth and on the growth hormone-insulin-like-growth factor (GH-IGF) system. EE treatment significantly reduced food conversion, body condition, and body growth. EE-inhibited growth resulted from alterations in peripheral elements of the GH-IGF system, which includes multiple GH receptors (GHRs), IGFs, and IGF receptors (IGFRs). In general, E2, βS, and NP reduced the expression of GHRs, IGFs, and IGFRs; however, the effects varied in an EE-, tissue-, element type-specific manner. For example, in liver, E2 was more efficacious than either βS, and NP in reducing GHR expression, and the effect of E2 was greater on GHR 1 than GHR2 mRNA. By contrast, in gill, all EEs affected GHR expression in a similar manner and there was no difference in the effect on GHR1 and GHR 2 mRNA. With regard to IGF expression, all EEs reduced hepatic IGF1 and IGF2 mRNA levels, whereas as in gill, only E2 and NP significantly reduced IGF1 and IGF2 expression. Lastly, E2 and NP reduced the expression of IGFR1A and IGFR1B mRNA expression similarly in gill and red and white muscle, whereas βS had no effect on expression of IGFR mRNAs. These findings indicate that EEs disrupt post-embryonic growth by reducing GH sensitivity, IGF production, and IGF sensitivity.

  9. HDAC I inhibition in the dorsal and ventral hippocampus differentially modulates predator-odor fear learning and generalization.

    PubMed

    Yuan, Robin K; Hebert, Jenna C; Thomas, Arthur S; Wann, Ellen G; Muzzio, Isabel A

    2015-01-01

    Although predator odors are ethologically relevant stimuli for rodents, the molecular pathways and contribution of some brain regions involved in predator odor conditioning remain elusive. Inhibition of histone deacetylases (HDACs) in the dorsal hippocampus has been shown to enhance shock-induced contextual fear learning, but it is unknown if HDACs have differential effects along the dorso-ventral hippocampal axis during predator odor fear learning. We injected MS-275, a class I HDAC inhibitor, bilaterally in the dorsal or ventral hippocampus of mice and found that it had no effects on innate anxiety in either region. We then assessed the effects of MS-275 at different stages of fear learning along the longitudinal hippocampal axis. Animals were injected with MS-275 or vehicle after context pre-exposure (pre-conditioning injections), when a representation of the context is first formed, or after exposure to coyote urine (post-conditioning injections), when the context becomes associated with predator odor. When MS-275 was administered after context pre-exposure, dorsally injected animals showed enhanced fear in the training context but were able to discriminate it from a neutral environment. Conversely, ventrally injected animals did not display enhanced learning in the training context but generalized the fear response to a neutral context. However, when MS-275 was administered after conditioning, there were no differences between the MS-275 and vehicle control groups in either the dorsal or ventral hippocampus. Surprisingly, all groups displayed generalization to a neutral context, suggesting that predator odor exposure followed by a mild stressor such as restraint leads to fear generalization. These results may elucidate distinct functions of the dorsal and ventral hippocampus in predator odor-induced fear conditioning as well as some of the molecular mechanisms underlying fear generalization. PMID:26441495

  10. Amyloid-PET predicts inhibition of de novo plaque formation upon chronic γ-secretase modulator treatment

    PubMed Central

    Brendel, M; Jaworska, A; Herms, J; Trambauer, J; Rötzer, C; Gildehaus, F-J; Carlsen, J; Cumming, P; Bylund, J; Luebbers, T; Bartenstein, P; Steiner, H; Haass, C; Baumann, K; Rominger, A

    2015-01-01

    In a positron-emission tomography (PET) study with the β-amyloid (Aβ) tracer [18F]-florbetaben, we previously showed that Aβ deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aβ42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5–a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aβ-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg−1) treatment for 6 months. A total of 131 Aβ-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aβ were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aβ42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aβ-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover

  11. Molecular mechanisms for inhibition of colon cancer cells by combined epigenetic-modulating epigallocatechin gallate and sodium butyrate

    SciTech Connect

    Saldanha, Sabita N.; Kala, Rishabh; Tollefsbol, Trygve O.

    2014-05-15

    Bioactive compounds are considered safe and have been shown to alter genetic and epigenetic profiles of tumor cells. However, many of these changes have been reported at molecular concentrations higher than physiologically achievable levels. We investigated the role of the combinatorial effects of epigallocatechin gallate (EGCG), a predominant polyphenol in green tea, and sodium butyrate (NaB), a dietary microbial fermentation product of fiber, in the regulation of survivin, which is an overexpressed anti-apoptotic protein in colon cancer cells. For the first time, our study showed that the combination treatment induced apoptosis and cell cycle arrest in RKO, HCT-116 and HT-29 colorectal cancer cells. This was found to be regulated by the decrease in HDAC1, DNMT1, survivin and HDAC activity in all three cell lines. A G2/M arrest was observed for RKO and HCT-116 cells, and G1 arrest for HT-29 colorectal cancer cells for combinatorial treatment. Further experimentation of the molecular mechanisms in RKO colorectal cancer (CRC) cells revealed a p53-dependent induction of p21 and an increase in nuclear factor kappa B (NF-κB)-p65. An increase in double strand breaks as determined by gamma-H2A histone family member X (γ-H2AX) protein levels and induction of histone H3 hyperacetylation was also observed with the combination treatment. Further, we observed a decrease in global CpG methylation. Taken together, these findings suggest that at low and physiologically achievable concentrations, combinatorial EGCG and NaB are effective in promoting apoptosis, inducing cell cycle arrest and DNA-damage in CRC cells. - Highlights: • EGCG and NaB as a combination inhibits colorectal cancer cell proliferation. • The combination treatment induces DNA damage, G2/M and G1 arrest and apoptosis. • Survivin is effectively down-regulated by the combination treatment. • p21 and p53 expressions are induced by the combination treatment. • Epigenetic proteins DNMT1 and HDAC1 are

  12. Pharmacologic inhibition of the CK2-mediated phosphorylation of B23/NPM in cancer cells selectively modulates genes related to protein synthesis, energetic metabolism, and ribosomal biogenesis.

    PubMed

    Perera, Yasser; Pedroso, Seidy; Borras-Hidalgo, Orlando; Vázquez, Dania M; Miranda, Jamilet; Villareal, Adelaida; Falcón, Viviana; Cruz, Luis D; Farinas, Hernán G; Perea, Silvio E

    2015-06-01

    B23/NPM is a multifunctional nucleolar protein frequently overexpressed, mutated, or rearranged in neoplastic tissues. B23/NPM is involved in diverse biological processes and is mainly regulated by heteroligomer association and posttranslational modification, phosphorylation being a major posttranslational event. While the role of B23/NPM in supporting and/or driving malignant transformation is widely recognized, the particular relevance of its CK2-mediated phosphorylation remains unsolved. Interestingly, the pharmacologic inhibition of such phosphorylation event by CIGB-300, a clinical-grade peptide drug, was previously associated to apoptosis induction in tumor cell lines. In this work, we sought to identify the biological processes modulated by CIGB-300 in a lung cancer cell line using subtractive suppression hybridization and subsequent functional annotation clustering. Our results indicate that CIGB-300 modulates a subset of genes involved in protein synthesis (ES = 8.4, p < 0.001), mitochondrial ATP metabolism (ES = 2.5, p < 0.001), and ribosomal biogenesis (ES = 1.5, p < 0.05). The impairment of these cellular processes by CIGB-300 was corroborated at the molecular and cellular levels by Western blot (P-S6/P-4EBP1, translation), confocal microscopy (JC-1, mitochondrial potential), qPCR (45SrRNA/p21, ribosome biogenesis), and electron microscopy (nucleolar structure, ribosome biogenesis). Altogether, our findings provide new insights on the potential relevance of the CK2-mediated phosphorylation of B23/NPM in cancer cells, revealing at the same time the potentialities of its pharmacological manipulation for cancer therapy. Finally, this work also suggests several candidate gene biomarkers to be evaluated during the clinical development of the anti-CK2 peptide CIGB-300.

  13. MEK Inhibition Sensitizes Precursor B-Cell Acute Lymphoblastic Leukemia (B-ALL) Cells to Dexamethasone through Modulation of mTOR Activity and Stimulation of Autophagy

    PubMed Central

    Polak, Anna; Kiliszek, Przemysław; Sewastianik, Tomasz; Szydłowski, Maciej; Jabłońska, Ewa; Białopiotrowicz, Emilia; Górniak, Patryk; Markowicz, Sergiusz; Nowak, Eliza; Grygorowicz, Monika A.; Prochorec-Sobieszek, Monika; Nowis, Dominika; Gołąb, Jakub; Giebel, Sebastian; Lech-Marańda, Ewa; Warzocha, Krzysztof; Juszczyński, Przemysław

    2016-01-01

    Resistance to glucocorticosteroids (GCs) is a major adverse prognostic factor in B-ALL, but the molecular mechanisms leading to GC resistance are not completely understood. Herein, we sought to elucidate the molecular background of GC resistance in B-ALL and characterize the therapeutic potential of targeted intervention in these mechanisms. Using exploratory bioinformatic approaches, we found that resistant cells exhibited significantly higher expression of MEK/ERK (MAPK) pathway components. We found that GC-resistant ALL cell lines had markedly higher baseline activity of MEK and small-molecule MEK1/2 inhibitor selumetinib increased GCs-induced cell death. MEK inhibitor similarly increased in vitro dexamethasone activity in primary ALL blasts from 19 of 22 tested patients. To further confirm these observations, we overexpressed a constitutively active MEK mutant in GC-sensitive cells and found that forced MEK activity induced resistance to dexamethasone. Since recent studies highlight the role GC-induced autophagy upstream of apoptotic cell death, we assessed LC3 processing, MDC staining and GFP-LC3 relocalization in cells incubated with either DEX, SEL or combination of drugs. Unlike either drug alone, only their combination markedly increased these markers of autophagy. These changes were associated with decreased mTOR activity and blocked 4E-BP1 phosphorylation. In cells with silenced beclin-1 (BCN1), required for autophagosome formation, the synergy of DEX and SEL was markedly reduced. Taken together, we show that MEK inhibitor selumetinib enhances dexamethasone toxicity in GC-resistant B-ALL cells. The underlying mechanism of this interaction involves inhibition of mTOR signaling pathway and modulation of autophagy markers, likely reflecting induction of this process and required for cell death. Thus, our data demonstrate that modulation of MEK/ERK pathway is an attractive therapeutic strategy overcoming GC resistance in B-ALL patients. PMID:27196001

  14. Isorhamnetin Inhibits Proliferation and Invasion and Induces Apoptosis through the Modulation of Peroxisome Proliferator-activated Receptor γ Activation Pathway in Gastric Cancer*

    PubMed Central

    Ramachandran, Lalitha; Manu, Kanjoormana Aryan; Shanmugam, Muthu K.; Li, Feng; Siveen, Kodappully Sivaraman; Vali, Shireen; Kapoor, Shweta; Abbasi, Taher; Surana, Rohit; Smoot, Duane T.; Ashktorab, Hassan; Tan, Patrick; Ahn, Kwang Seok; Yap, Chun Wei; Kumar, Alan Prem; Sethi, Gautam

    2012-01-01

    Gastric cancer (GC) is a lethal malignancy and the second most common cause of cancer-related deaths. Although treatment options such as chemotherapy, radiotherapy, and surgery have led to a decline in the mortality rate due to GC, chemoresistance remains as one of the major causes for poor prognosis and high recurrence rate. In this study, we investigated the potential effects of isorhamnetin (IH), a 3′-O-methylated metabolite of quercetin on the peroxisome proliferator-activated receptor γ (PPAR-γ) signaling cascade using proteomics technology platform, GC cell lines, and xenograft mice model. We observed that IH exerted a strong antiproliferative effect and increased cytotoxicity in combination with chemotherapeutic drugs. IH also inhibited the migratory/invasive properties of GC cells, which could be reversed in the presence of PPAR-γ inhibitor. We found that IH increased PPAR-γ activity and modulated the expression of PPAR-γ regulated genes in GC cells. Also, the increase in PPAR-γ activity was reversed in the presence of PPAR-γ-specific inhibitor and a mutated PPAR-γ dominant negative plasmid, supporting our hypothesis that IH can act as a ligand of PPAR-γ. Using molecular docking analysis, we demonstrate that IH formed interactions with seven polar residues and six nonpolar residues within the ligand-binding pocket of PPAR-γ that are reported to be critical for its activity and could competitively bind to PPAR-γ. IH significantly increased the expression of PPAR-γ in tumor tissues obtained from xenograft model of GC. Overall, our findings clearly indicate that antitumor effects of IH may be mediated through modulation of the PPAR-γ activation pathway in GC. PMID:22992727

  15. A heterocyclic compound CE-103 inhibits dopamine reuptake and modulates dopamine transporter and dopamine D1-D3 containing receptor complexes.

    PubMed

    Sase, Ajinkya; Aher, Yogesh D; Saroja, Sivaprakasam R; Ganesan, Minu Karthika; Sase, Sunetra; Holy, Marion; Höger, Harald; Bakulev, Vasiliy; Ecker, Gerhard F; Langer, Thierry; Sitte, Harald H; Leban, Johann; Lubec, Gert

    2016-03-01

    A series of compounds have been reported to enhance memory via the DA system and herein a heterocyclic compound was tested for working memory (WM) enhancement. 2-((benzhydrylsulfinyl)methyl)thiazole (CE-103) was synthesized in a six-step synthesis. Binding of CE-103 to the dopamine (DAT), serotonin (SERT) and norepinephrine (NET) transporters and dopamine reuptake inhibition was tested as well as blood brain permeation and a screen for GPCR targets. 60 male Sprague Dawley rats were divided into six groups: CE-103 treated 1-10 mg/kg body weight, trained (TDI) and yoked (YDI) and vehicle treated, trained (TVI) and yoked (YVI) rats. Daily single intraperitoneal injections for a period of 10 days were administered and rats were tested in a radial arm maze (RAM). Hippocampi were taken 6 h following the last day of training and complexes containing the unphosphorylated or phosphorylated dopamine transporter (DAT) and complexes containing the D1-3 dopamine receptor subunits were determined. CE-103 was binding to the DAT but insignificantly to SERT or NET and dopamine reuptake was blocked specifically (IC50 = 14.73 μM). From day eight the compound was decreasing WM errors in the RAM significantly at both doses tested as compared to the vehicle controls. In the trained CE-103-treated group levels of the complex containing the phosphorylated dopamine transporter (pDAT) as well as D1R were decreased while levels of complexes containing D2R and D3R were significantly increased. CE-103 was shown to enhance spatial WM and DA reuptake inhibition with subsequent modulation of D1-3 receptors is proposed as a possible mechanism of action. PMID:26407764

  16. Modulation of mGlu2 Receptors, but Not PDE10A Inhibition Normalizes Pharmacologically-Induced Deviance in Auditory Evoked Potentials and Oscillations in Conscious Rats

    PubMed Central

    Ahnaou, Abdallah; Biermans, Ria; Drinkenburg, Wilhelmus H.

    2016-01-01

    Improvement of cognitive impairments represents a high medical need in the development of new antipsychotics. Aberrant EEG gamma oscillations and reductions in the P1/N1 complex peak amplitude of the auditory evoked potential (AEP) are neurophysiological biomarkers for schizophrenia that indicate disruption in sensory information processing. Inhibition of phosphodiesterase (i.e. PDE10A) and activation of metabotropic glutamate receptor (mGluR2) signaling are believed to provide antipsychotic efficacy in schizophrenia, but it is unclear whether this occurs with cognition-enhancing potential. The present study used the auditory paired click paradigm in passive awake Sprague Dawley rats to 1) model disruption of AEP waveforms and oscillations as observed in schizophrenia by peripheral administration of amphetamine and the N-methyl-D-aspartate (NMDA) antagonist phencyclidine (PCP); 2) confirm the potential of the antipsychotics risperidone and olanzapine to attenuate these disruptions; 3) evaluate the potential of mGluR2 agonist LY404039 and PDE10 inhibitor PQ-10 to improve AEP deficits in both the amphetamine and PCP models. PCP and amphetamine disrupted auditory information processing to the first click, associated with suppression of the P1/N1 complex peak amplitude, and increased cortical gamma oscillations. Risperidone and olanzapine normalized PCP and amphetamine-induced abnormalities in AEP waveforms and aberrant gamma/alpha oscillations, respectively. LY404039 increased P1/N1 complex peak amplitudes and potently attenuated the disruptive effects of both PCP and amphetamine on AEPs amplitudes and oscillations. However, PQ-10 failed to show such effect in either models. These outcomes indicate that modulation of the mGluR2 results in effective restoration of abnormalities in AEP components in two widely used animal models of psychosis, whereas PDE10A inhibition does not. PMID:26808689

  17. Baicalein inhibition of oxidative-stress-induced apoptosis via modulation of ERKs activation and induction of HO-1 gene expression in rat glioma cells C6

    SciTech Connect

    Chen, Y.-C. . E-mail: yc3270@tmu.edu.tw; Chow, J.-M.; Lin, C.-W.; Wu, C.-Y.; Shen, S.-C.

    2006-10-15

    in C6 cells. However, BE treatment was unable to protect C6 cells from C2-ceramide-induced cell death. These data indicate that BE possesses abilities to inhibit ROS-mediated cytotoxic effects through modulation of ERKs activation and induction of HO-1 protein expression. The role of HO-1 in ROS-scavenging activity of BE is proposed.

  18. Pterostilbene inhibits triple-negative breast cancer metastasis via inducing microRNA-205 expression and negatively modulates epithelial-to-mesenchymal transition.

    PubMed

    Su, Chih-Ming; Lee, Wei-Hwa; Wu, Alexander T H; Lin, Yen-Kuang; Wang, Liang-Shun; Wu, Chih-Hsiung; Yeh, Chi-Tai

    2015-06-01

    Breast cancer is the leading cause of cancer-related deaths among females in economically developing countries. Greater than 95% of breast malignancies are of epithelial origin; the induction of epithelial-to-mesenchymal transition (EMT) has been shown to initiate the metastatic process in breast carcinoma and remains the key target for drug development. Here, we examine the anti-metastatic potential of pterostilbene in modulating EMT process in breast cancer cells both in vitro and in vivo. The differential invasive ability among MCF7, Hs578t and MDA-MB-231 breast cancer cell lines were closely correlated with the expression of EMT markers, determined by Western blots and Matrigel-coated transwells assay. Pterostilbene inhibited the migratory and invasive potential of triple-negative MDA-MB-231 and Hs578t cells, accompanied by the up-regulation of E-cadherin and down-regulation of Snail, Slug, vimentin and ZEB1. Mechanistic investigations revealed a significant up-regulation of miR-205, which resulted in the reduction of Src expression in pterostilbene-treated breast cancer cells. Importantly, pterostilbene suppressed tumor growth and metastasis in MDA-MB-231-bearing NOD/SCID mice by reducing Src/Fak signaling; this observation was consistent with the negative correlations between miR-205 and Src expression in both normal and malignant breast tissues. Our findings provide supports for the usage of pterostilbene as an inhibitor of EMT process and potential candidate for adjuvant therapy. PMID:25792283

  19. Post-exposure administration of diazepam combined with soluble epoxide hydrolase inhibition stops seizures and modulates neuroinflammation in a murine model of acute TETS intoxication

    SciTech Connect

    Vito, Stephen T.; Austin, Adam T.; Banks, Christopher N.; Inceoglu, Bora; Bruun, Donald A.; Zolkowska, Dorota; Tancredi, Daniel J.; Rogawski, Michael A.; Hammock, Bruce D.; Lein, Pamela J.

    2014-12-01

    Tetramethylenedisulfotetramine (TETS) is a potent convulsant poison for which there is currently no approved antidote. The convulsant action of TETS is thought to be mediated by inhibition of type A gamma-aminobutyric acid receptor (GABA{sub A}R) function. We, therefore, investigated the effects of post-exposure administration of diazepam, a GABA{sub A}R positive allosteric modulator, on seizure activity, death and neuroinflammation in adult male Swiss mice injected with a lethal dose of TETS (0.15 mg/kg, ip). Administration of a high dose of diazepam (5 mg/kg, ip) immediately following the second clonic seizure (approximately 20 min post-TETS injection) effectively prevented progression to tonic seizures and death. However, this treatment did not prevent persistent reactive astrogliosis and microglial activation, as determined by GFAP and Iba-1 immunoreactivity and microglial cell morphology. Inhibition of soluble epoxide hydrolase (sEH) has been shown to exert potent anti-inflammatory effects and to increase survival in mice intoxicated with other GABA{sub A}R antagonists. The sEH inhibitor TUPS (1 mg/kg, ip) administered immediately after the second clonic seizure did not protect TETS-intoxicated animals from tonic seizures or death. Combined administration of diazepam (5 mg/kg, ip) and TUPS (1 mg/kg, ip, starting 1 h after diazepam and repeated every 24 h) prevented TETS-induced lethality and influenced signs of neuroinflammation in some brain regions. Significantly decreased microglial activation and enhanced reactive astrogliosis were observed in the hippocampus, with no changes in the cortex. Combining an agent that targets specific anti-inflammatory mechanisms with a traditional antiseizure drug may enhance treatment outcome in TETS intoxication. - Highlights: • Acute TETS intoxication causes delayed and persistent neuroinflammation. • Diazepam given post-TETS prevents lethal tonic seizures but not neuroinflammation. • A soluble epoxide hydrolase

  20. ANKRD1 modulates inflammatory responses in C2C12 myoblasts through feedback inhibition of NF-κB signaling activity

    SciTech Connect

    Liu, Xin-Hua; Bauman, William A.; Cardozo, Christopher

    2015-08-14

    Transcription factors of the nuclear factor-kappa B (NF-κB) family play a pivotal role in inflammation, immunity and cell survival responses. Recent studies revealed that NF-κB also regulates the processes of muscle atrophy. NF-κB activity is regulated by various factors, including ankyrin repeat domain 2 (AnkrD2), which belongs to the muscle ankyrin repeat protein family. Another member of this family, AnkrD1 is also a transcriptional effector. The expression levels of AnkrD1 are highly upregulated in denervated skeletal muscle, suggesting an involvement of AnkrD1 in NF-κB mediated cellular responses to paralysis. However, the molecular mechanism underlying the interactive role of AnkrD1 in NF-κB mediated cellular responses is not well understood. In the current study, we examined the effect of AnkrD1 on NF-κB activity and determined the interactions between AnkrD1 expression and NF-κB signaling induced by TNFα in differentiating C2C12 myoblasts. TNFα upregulated AnkrD1 mRNA and protein levels. AnkrD1-siRNA significantly increased TNFα-induced transcriptional activation of NF-κB, whereas overexpression of AnkrD1 inhibited TNFα-induced NF-κB activity. Co-immunoprecipitation studies demonstrated that AnkrD1 was able to bind p50 subunit of NF-κB and vice versa. Finally, CHIP assays revealed that AnkrD1 bound chromatin at a NF-κB binding site in the AnrkD2 promoter and required NF-κB to do so. These results provide evidence of signaling integration between AnkrD1 and NF-κB pathways, and suggest a novel anti-inflammatory role of AnkrD1 through feedback inhibition of NF-κB transcriptional activity by which AnkrD1 modulates the balance between physiological and pathological inflammatory responses in skeletal muscle. - Highlights: • AnkrD1 is upregulated by TNFα and represses NF-κB-induced transcriptional activity. • AnkrD1 binds to p50 subunit of NF-κB and is recruited to NF-κB bound to chromatin. • AnkrD1 mediates a feed-back inhibitory loop

  1. ANKRD1 modulates inflammatory responses in C2C12 myoblasts through feedback inhibition of NF-κB signaling activity.

    PubMed

    Liu, Xin-Hua; Bauman, William A; Cardozo, Christopher

    2015-08-14

    Transcription factors of the nuclear factor-kappa B (NF-κB) family play a pivotal role in inflammation, immunity and cell survival responses. Recent studies revealed that NF-κB also regulates the processes of muscle atrophy. NF-κB activity is regulated by various factors, including ankyrin repeat domain 2 (AnkrD2), which belongs to the muscle ankyrin repeat protein family. Another member of this family, AnkrD1 is also a transcriptional effector. The expression levels of AnkrD1 are highly upregulated in denervated skeletal muscle, suggesting an involvement of AnkrD1 in NF-κB mediated cellular responses to paralysis. However, the molecular mechanism underlying the interactive role of AnkrD1 in NF-κB mediated cellular responses is not well understood. In the current study, we examined the effect of AnkrD1 on NF-κB activity and determined the interactions between AnkrD1 expression and NF-κB signaling induced by TNFα in differentiating C2C12 myoblasts. TNFα upregulated AnkrD1 mRNA and protein levels. AnkrD1-siRNA significantly increased TNFα-induced transcriptional activation of NF-κB, whereas overexpression of AnkrD1 inhibited TNFα-induced NF-κB activity. Co-immunoprecipitation studies demonstrated that AnkrD1 was able to bind p50 subunit of NF-κB and vice versa. Finally, CHIP assays revealed that AnkrD1 bound chromatin at a NF-κB binding site in the AnrkD2 promoter and required NF-κB to do so. These results provide evidence of signaling integration between AnkrD1 and NF-κB pathways, and suggest a novel anti-inflammatory role of AnkrD1 through feedback inhibition of NF-κB transcriptional activity by which AnkrD1 modulates the balance between physiological and pathological inflammatory responses in skeletal muscle. PMID:26102030

  2. Rosiglitazone inhibits chlorpyrifos-induced apoptosis via modulation of the oxidative stress and inflammatory response in SH-SY5Y cells

    SciTech Connect

    Lee, Jeong Eun; Park, Jae Hyeon; Jang, Sea Jeong; Koh, Hyun Chul

    2014-07-15

    Oxidative stress can lead to expression of inflammatory transcription factors, which are important regulatory elements in the induction of inflammatory responses. One of the transcription factors, nuclear transcription factor kappa-B (NF-κB) plays a significant role in the inflammation regulatory process. Inflammatory cell death has been implicated in neuronal cell death in some neurodegenerative disorders such as Parkinson's disease (PD). In this study, we investigated the molecular mechanisms underlying apoptosis initiated by chlorpyrifos (CPF)-mediated oxidative stress. Based on the cytotoxic mechanism of CPF, we examined the neuroprotective effects of rosiglitazone (RGZ), a peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist, against CPF-induced neuronal cell death. The treatment of SH-SY5Y cells with CPF induced oxidative stress. In addition, CPF activated the p38, JNK and ERK mitogen-activated protein kinases (MAPKs), and induced increases in the inflammatory genes such as COX-2 and TNF-α. CPF also induced nuclear translocation of NF-κB and inhibitors of NF-κB abolished the CPF-induced COX-2 expression. Pretreatment with RGZ significantly reduced ROS generation and enhanced HO-1 expression in CPF-exposed cells. RGZ blocked the activation of both p38 and JNK signaling, while ERK activation was strengthened. RGZ also attenuated CPF-induced cell death through the reduction of NF-κB-mediated proinflammatory factors. Results from this study suggest that RGZ may exert an anti-apoptotic effect against CPF-induced cytotoxicity by attenuation of oxidative stress as well as inhibition of the inflammatory cascade via inactivation of signaling by p38 and JNK, and NF-κB. - Highlights: • CPF induces apoptotic cell death in SH-SY5Y cells • ROS involved in CPF-mediated apoptotic cell death • Inflammation involved in CPF-mediated apoptotic cell death • Rosiglitazone modulates ROS and inflammatory response in CPF-treated cells.

  3. Phyllanthus spp. Induces Selective Growth Inhibition of PC-3 and MeWo Human Cancer Cells through Modulation of Cell Cycle and Induction of Apoptosis

    PubMed Central

    Tang, Yin-Quan; Jaganath, Indu Bala; Sekaran, Shamala Devi

    2010-01-01

    Background Phyllanthus is a traditional medicinal plant that has been used in the treatment of many diseases including hepatitis and diabetes. The main aim of the present work was to investigate the potential cytotoxic effects of aqueous and methanolic extracts of four Phyllanthus species (P.amarus, P.niruri, P.urinaria and P.watsonii) against skin melanoma and prostate cancer cells. Methodology/Principal Findings Phyllanthus plant appears to possess cytotoxic properties with half-maximal inhibitory concentration (IC50) values of 150–300 µg/ml for aqueous extract and 50–150 µg/ml for methanolic extract that were determined using the MTS reduction assay. In comparison, the plant extracts did not show any significant cytotoxicity on normal human skin (CCD-1127Sk) and prostate (RWPE-1) cells. The extracts appeared to act by causing the formation of a clear “ladder” fragmentation of apoptotic DNA on agarose gel, displayed TUNEL-positive cells with an elevation of caspase-3 and -7 activities. The Lactate Dehydrogenase (LDH) level was lower than 15% in Phyllanthus treated-cancer cells. These indicate that Phyllanthus extracts have the ability to induce apoptosis with minimal necrotic effects. Furthermore, cell cycle analysis revealed that Phyllanthus induced a Go/G1-phase arrest on PC-3 cells and a S-phase arrest on MeWo cells and these were accompanied by accumulation of cells in the Sub-G1 (apoptosis) phase. The cytotoxic properties may be due to the presence of polyphenol compounds such as ellagitannins, gallotannins, flavonoids and phenolic acids found both in the water and methanol extract of the plants. Conclusions/Significance Phyllanthus plant exerts its growth inhibition effect in a selective manner towards cancer cells through the modulation of cell cycle and induction of apoptosis via caspases activation in melanoma and prostate cancer cells. Hence, Phyllanthus may be sourced for the development of a potent apoptosis-inducing anticancer agent. PMID

  4. Brain endothelial miR-146a negatively modulates T-cell adhesion through repressing multiple targets to inhibit NF-κB activation

    PubMed Central

    Wu, Dongsheng; Cerutti, Camilla; Lopez-Ramirez, Miguel A; Pryce, Gareth; King-Robson, Josh; Simpson, Julie E; van der Pol, Susanne MA; Hirst, Mark C; de Vries, Helga E; Sharrack, Basil; Baker, David; Male, David K; Michael, Gregory J; Romero, Ignacio A

    2015-01-01

    Pro-inflammatory cytokine-induced activation of nuclear factor, NF-κB has an important role in leukocyte adhesion to, and subsequent migration across, brain endothelial cells (BECs), which is crucial for the development of neuroinflammatory disorders such as multiple sclerosis (MS). In contrast, microRNA-146a (miR-146a) has emerged as an anti-inflammatory molecule by inhibiting NF-κB activity in various cell types, but its effect in BECs during neuroinflammation remains to be evaluated. Here, we show that miR-146a was upregulated in microvessels of MS-active lesions and the spinal cord of mice with experimental autoimmune encephalomyelitis. In vitro, TNFα and IFNγ treatment of human cerebral microvascular endothelial cells (hCMEC/D3) led to upregulation of miR-146a. Brain endothelial overexpression of miR-146a diminished, whereas knockdown of miR-146a augmented cytokine-stimulated adhesion of T cells to hCMEC/D3 cells, nuclear translocation of NF-κB, and expression of adhesion molecules in hCMEC/D3 cells. Furthermore, brain endothelial miR-146a modulates NF-κB activity upon cytokine activation through targeting two novel signaling transducers, RhoA and nuclear factor of activated T cells 5, as well as molecules previously identified, IL-1 receptor-associated kinase 1, and TNF receptor-associated factor 6. We propose brain endothelial miR-146a as an endogenous NF-κB inhibitor in BECs associated with decreased leukocyte adhesion during neuroinflammation. PMID:25515214

  5. Serum from patients with erectile dysfunction inhibits circulating angiogenic cells from healthy men: relationship with cardiovascular risk, endothelial damage and circulating angiogenic modulators.

    PubMed

    Pelliccione, F; D'Angeli, A; Filipponi, S; Falone, S; Necozione, S; Barbonetti, A; Francavilla, F; Francavilla, S

    2012-10-01

    Erectile dysfunction (ED) is an early manifestation of arteriosclerosis associated with endothelial damage/dysfunction and to a blunted ability of cultured mononuclear circulating cells (MNCs) to differentiate circulating angiogenic cells (CACs), putatively involved in endothelial damage repair. Here we explored effects of human serum (HS) from patients with ED and cardiovascular risk factors (VRFs) but no clinical atherosclerosis, on cultured MNCs of healthy men to differentiate CACs and to form colonies. Effect of HS on number of CACS and of colony forming units (CFUs) was correlated with circulating markers of endothelial damage and with angiogenic modulators. MNCs from healthy men were cultured in standard conditions or with 20% HS from 35 patients with ED and from 10 healthy men. CACs were identified after 7 days of culture by uptake of acetylated low-density lipoprotein with concomitant binding of Ulex europaeus agglutinin I. CFUs were counted after 5 days of culture. Enzyme-linked immunosorbent assays assessed plasmatic soluble (s) form of E-selectin, Endothelin (ET)-1, tissue type plasminogen activator (tPA), vascular endothelial growth factor (VEGF)(165) and sVEGF receptor (R)-1. The number of CACs and of CFUs from healthy men was reduced after culturing MNCs with HS compared to standard medium. The inhibitory effect was significantly higher with HS from ED patients with higher or lower VRF exposure compared to healthy men. Inhibition was positively correlated with VRFs exposure, with ED severity, with common carotid artery intima media thickness measured using B-mode ultrasound, and to a lesser extent with plasmatic sE-Selectin, sET-1 and sVEGFR-1. Dysfunction of cells involved in vascular homoeostasis is induced by soluble factors still unknown and already present in a very initial systemic vascular disease in men with ED and VRFs. PMID:22394130

  6. Modulation of the oscillatory mechanics of lung tissue and the oxidative stress response induced by arginase inhibition in a chronic allergic inflammation model

    PubMed Central

    2013-01-01

    Background The importance of the lung parenchyma in the pathophysiology of asthma has previously been demonstrated. Considering that nitric oxide synthases (NOS) and arginases compete for the same substrate, it is worthwhile to elucidate the effects of complex NOS-arginase dysfunction in the pathophysiology of asthma, particularly, related to distal lung tissue. We evaluated the effects of arginase and iNOS inhibition on distal lung mechanics and oxidative stress pathway activation in a model of chronic pulmonary allergic inflammation in guinea pigs. Methods Guinea pigs were exposed to repeated ovalbumin inhalations (twice a week for 4 weeks). The animals received 1400 W (an iNOS-specific inhibitor) for 4 days beginning at the last inhalation. Afterwards, the animals were anesthetized and exsanguinated; then, a slice of the distal lung was evaluated by oscillatory mechanics, and an arginase inhibitor (nor-NOHA) or vehicle was infused in a Krebs solution bath. Tissue resistance (Rt) and elastance (Et) were assessed before and after ovalbumin challenge (0.1%), and lung strips were submitted to histopathological studies. Results Ovalbumin-exposed animals presented an increase in the maximal Rt and Et responses after antigen challenge (p<0.001), in the number of iNOS positive cells (p<0.001) and in the expression of arginase 2, 8-isoprostane and NF-kB (p<0.001) in distal lung tissue. The 1400 W administration reduced all these responses (p<0.001) in alveolar septa. Ovalbumin-exposed animals that received nor-NOHA had a reduction of Rt, Et after antigen challenge, iNOS positive cells and 8-isoprostane and NF-kB (p<0.001) in lung tissue. The activity of arginase 2 was reduced only in the groups treated with nor-NOHA (p <0.05). There was a reduction of 8-isoprostane expression in OVA-NOR-W compared to OVA-NOR (p<0.001). Conclusions In this experimental model, increased arginase content and iNOS-positive cells were associated with the constriction of distal lung parenchyma

  7. MiR-630 inhibits proliferation by targeting CDC7 kinase, but maintains the apoptotic balance by targeting multiple modulators in human lung cancer A549 cells

    PubMed Central

    Cao, J-X; Lu, Y; Qi, J-J; An, G-S; Mao, Z-B; Jia, H-T; Li, S-Y; Ni, J-H

    2014-01-01

    MicroRNAome analyses have shown microRNA-630 (miR-630) to be involved in the regulation of apoptosis. However, its apoptotic role is still debated and its participation in DNA replication is unknown. Here, we demonstrate that miR-630 inhibits cell proliferation by targeting cell-cycle kinase 7 (CDC7) kinase, but maintains the apoptotic balance by targeting multiple activators of apoptosis under genotoxic stress. We identified a novel regulatory mechanism of CDC7 gene expression, in which miR-630 downregulated CDC7 expression by recognizing and binding to four binding sites in CDC7 3'-UTR. We found that miR-630 was highly expressed in A549 and NIH3T3 cells where CDC7 was downregulated, but lower in H1299, MCF7, MDA-MB-231, HeLa and 2BS cells where CDC7 was upregulated. Furthermore, the induction of miR-630 occurred commonly in a variety of human cancer and immortalized cells in response to genotoxic agents. Importantly, downregulation of CDC7 by miR-630 was associated with cisplatin (CIS)-induced inhibitory proliferation in A549 cells. Mechanistically, miR-630 exerted its inhibitory proliferation by blocking CDC7-mediated initiation of DNA synthesis and by inducing G1 arrest, but maintains apoptotic balance under CIS exposure. On the one hand, miR-630 promoted apoptosis by downregulation of CDC7; on the other hand, it reduced apoptosis by downregulating several apoptotic modulators such as PARP3, DDIT4, EP300 and EP300 downstream effector p53, thereby maintaining the apoptotic balance. Our data indicate that miR-630 has a bimodal role in the regulation of apoptosis in response to DNA damage. Our data also support the notion that a certain mRNA can be targeted by several miRNAs, and in particular an miRNA may target a set of mRNAs. These data afford a comprehensive view of microRNA-dependent control of gene expression in the regulation of apoptosis under genotoxic stress. PMID:25255219

  8. Modified Panax ginseng Extract Inhibits uPAR-Mediated α[Formula: see text]β1-Integrin Signaling by Modulating Caveolin-1 to Induce Early Apoptosis in Lung Cancer Cells.

    PubMed

    Hwang, In-Hu; Kwon, Yong-Kyun; Cho, Chong-Kwan; Lee, Yeon-Weol; Sung, Jung-Suk; Joo, Jong-Cheon; Lee, Kyung-Bok; Yoo, Hwa-Seung; Jang, Ik-Soon

    2016-01-01

    Urokinase receptor (uPAR) is enhanced in many human cancer cells and is frequently an indicator of poor prognosis. Activation of [Formula: see text]1-integrin requires caveolin-1 and is regulated by uPAR. However, the underlying molecular mechanism responsible for the interaction between uPAR and [Formula: see text]1-integrin remains obscure. We found that modified regular Panax ginseng extract (MRGX) had a negative modulating effect on the uPAR/[Formula: see text]1-integrin interaction, disrupted the uPAR/integrin interaction by modulating caveoline-1, and caused early apoptosis in cancer cells. Additionally, we found that siRNA-mediated caveoline-1 downregulation inhibited uPAR-mediated [Formula: see text]1-integrin signaling, whereas caveoline-1 up-regulation stimulated the signaling, which suppressed p53 expression, thereby indicating negative crosstalk exists between the integrin [Formula: see text]1 and the p53 pathways. Thus, these findings identify a novel mechanism whereby the inhibition of [Formula: see text]1 integrin and the activation of p53 modulate the expression of the anti-apoptotic proteins that are crucially involved in inducing apoptosis in A549 lung cancer cells. Furthermore, MRGX causes changes in the expressions of members of the Bcl-2 family (Bax and Bcl-2) in a pro-apoptotic manner. In addition, MGRX-mediated inhibition of [Formula: see text]1 integrin attenuates ERK phosphorylation (p-ERK), which up-regulates caspase-8 and Bax. Therefore, ERK may affect mitochondria through a negative regulation of caspase-8 and Bax. Taken together, these findings reveal that MRGX is involved in uPAR-[Formula: see text]1-integrin signaling by modulating caveolin-1 signaling to induce early apoptosis in A549 lung-cancer cells and strongly indicate that MRGX might be useful as a herbal medicine and may lead to the development of new herbal medicine that would suppress the growth of lung-cancer cells.

  9. Mitigating the inhibition of human bile salt export pump by drugs: opportunities provided by physicochemical property modulation, in silico modeling, and structural modification.

    PubMed

    Warner, Daniel J; Chen, Hongming; Cantin, Louis-David; Kenna, J Gerry; Stahl, Simone; Walker, Clare L; Noeske, Tobias

    2012-12-01

    The human bile salt export pump (BSEP) is a membrane protein expressed on the canalicular plasma membrane domain of hepatocytes, which mediates active transport of unconjugated and conjugated bile salts from liver cells into bile. BSEP activity therefore plays an important role in bile flow. In humans, genetically inherited defects in BSEP expression or activity cause cholestatic liver injury, and many drugs that cause cholestatic drug-induced liver injury (DILI) in humans have been shown to inhibit BSEP activity in vitro and in vivo. These findings suggest that inhibition of BSEP activity by drugs could be one of the mechanisms that initiate human DILI. To gain insight into the chemical features responsible for BSEP inhibition, we have used a recently described in vitro membrane vesicle BSEP inhibition assay to quantify transporter inhibition for a set of 624 compounds. The relationship between BSEP inhibition and molecular physicochemical properties was investigated, and our results show that lipophilicity and molecular size are significantly correlated with BSEP inhibition. This data set was further used to build predictive BSEP classification models through multiple quantitative structure-activity relationship modeling approaches. The highest level of predictive accuracy was provided by a support vector machine model (accuracy = 0.87, κ = 0.74). These analyses highlight the potential value that can be gained by combining computational methods with experimental efforts in early stages of drug discovery projects to minimize the propensity of drug candidates to inhibit BSEP.

  10. Modulation of foot-and-mouth disease virus pH threshold for uncoating correlates with differential sensitivity to inhibition of cellular Rab GTPases and decreases infectivity in vivo.

    PubMed

    Vázquez-Calvo, Angela; Caridi, Flavia; Rodriguez-Pulido, Miguel; Borrego, Belén; Sáiz, Margarita; Sobrino, Francisco; Martín-Acebes, Miguel A

    2012-11-01

    The role of cellular Rab GTPases that govern traffic between different endosome populations was analysed on foot-and-mouth disease virus (FMDV) infection. Changes of viral receptor specificity did not alter Rab5 requirement for infection. However, a correlation between uncoating pH and requirement of Rab5 for infection was observed. A mutant FMDV with less acidic uncoating pH threshold was less sensitive to inhibition of Rab5, whereas another mutant with more acidic requirements was more sensitive to inhibition of Rab5. On the contrary, opposed correlations between uncoating pH and dependence of Rab function were observed upon expression of dominant-negative forms of Rab7 or 11. Modulation of uncoating pH also reduced FMDV virulence in suckling mice. These results are consistent with FMDV uncoating inside early endosomes and indicate that displacements from optimum pH for uncoating reduce viral fitness in vivo.

  11. Inhibition of GSK3 differentially modulates NF-{kappa}B, CREB, AP-1 and {beta}-catenin signaling in hepatocytes, but fails to promote TNF-{alpha}-induced apoptosis

    SciTech Connect

    Goetschel, Frank; Kern, Claudia; Lang, Simona; Sparna, Titus; Markmann, Cordula; Schwager, Joseph; McNelly, Sabine; Weizsaecker, Fritz von; Laufer, Stefan; Hecht, Andreas Merfort, Irmgard

    2008-04-01

    Glycogen synthase kinase-3 (GSK-3) is known to modulate cell survival and apoptosis through multiple intracellular signaling pathways. However, its hepatoprotective function and its role in activation of NF-{kappa}B and anti-apoptotic factors are poorly understood and remain controversial. Here we investigated whether inhibition of GSK-3 could induce apoptosis in the presence of TNF-{alpha} in primary mouse hepatocytes. We show that pharmacological inhibition of GSK-3 in primary mouse hepatocytes does not lead to TNF-{alpha}-induced apoptosis despite reduced NF-{kappa}B activity. Enhanced stability of I{kappa}B-{alpha} appears to be responsible for lower levels of nuclear NF-{kappa}B and hence reduced transactivation. Additionally, inhibition of GSK-3 was accompanied by marked upregulation of {beta}-catenin, AP-1, and CREB transcription factors. Stimulation of canonical Wnt signaling and CREB activity led to elevated levels of anti-apoptotic factors. Hence, survival of primary mouse hepatocytes may be caused by the activation and/or upregulation of other key regulators of liver homeostasis and regeneration. These signaling molecules may compensate for the compromised anti-apoptotic function of NF-{kappa}B and allow survival of hepatocytes in the presence of TNF-{alpha} and GSK-3 inhibition.

  12. Mechanism for Noncompetitive Inhibition by Novel GluN2C/D N-Methyl-d-aspartate Receptor Subunit-Selective ModulatorsS⃞

    PubMed Central

    Acker, Timothy M.; Yuan, Hongjie; Hansen, Kasper B.; Vance, Katie M.; Ogden, Kevin K.; Jensen, Henrik S.; Burger, Pieter B.; Mullasseril, Praseeda; Snyder, James P.; Liotta, Dennis C.

    2011-01-01

    The compound 4-(5-(4-bromophenyl)-3-(6-methyl-2-oxo-4-phenyl-1,2-dihydroquinolin-3-yl)-4,5-dihydro-1H-pyrazol-1-yl)-4-oxobutanoic acid (DQP-1105) is a representative member of a new class of N-methyl-d-aspartate (NMDA) receptor antagonists. DQP-1105 inhibited GluN2C- and GluN2D-containing receptors with IC50 values that were at least 50-fold lower than those for recombinant GluN2A-, GluN2B-, GluA1-, or GluK2-containing receptors. Inhibition was voltage-independent and could not be surmounted by increasing concentrations of either coagonist, glutamate or glycine, consistent with a noncompetitive mechanism of action. DQP-1105 inhibited single-channel currents in excised outside-out patches without significantly changing mean open time or single-channel conductance, suggesting that DQP inhibits a pregating step without changing the stability of the open pore conformation and thus channel closing rate. Evaluation of DQP-1105 inhibition of chimeric NMDA receptors identified two key residues in the lower lobe of the GluN2 agonist binding domain that control the selectivity of DQP-1105. These data suggest a mechanism for this new class of inhibitors and demonstrate that ligands can access, in a subunit-selective manner, a new site located in the lower, membrane-proximal portion of the agonist-binding domain. PMID:21807990

  13. PLK1 Inhibition Down-regulates Polycomb Group Protein BMI1 via Modulation of the miR-200c/141 Cluster*

    PubMed Central

    Dimri, Manjari; Cho, Joon-Ho; Kang, Mingu; Dimri, Goberdhan P.

    2015-01-01

    The polycomb group protein BMI1 is an important regulator of cancer stem cell (CSC) phenotype and is often overexpressed in cancer cells. Its overexpression leads to increase in CSC fraction and therapy resistance in tumors. BMI1 functions via polycomb repressive complex 1 (PRC1)-mediated gene silencing and also via PRC1-independent transcriptional activities. At present, very little is known about the therapy reagents that can efficiently inhibit BMI1 expression, and the CSC phenotype. Here, we report that the polo-like kinase 1 (PLK1) regulates BMI1 expression, and that its inhibition can efficiently down-regulate BMI1 expression and PRC1 activity, and induce premature senescence in breast cancer cells. We also show that the exogenous BMI1 overexpression mitigates anti-oncogenic effects of PLK1 inhibition and overcomes senescence induction by PLK1 inhibitors. We further show that PLK1 inhibition down-regulates BMI1 by upregulating the miRNA-200c/141 cluster, which encodes miR-200c and miR-141, both of which are known to post-transcriptionally downregulate BMI1 expression. Thus, our data suggest that PLK1 inhibitors can be successfully used to inhibit growth of tumors in which PcG protein BMI1 is overexpressed or the PRC1 activity is deregulated. PMID:25505268

  14. A Novel Pan-Negative-Gating Modulator of KCa2/3 Channels, Fluoro-Di-Benzoate, RA-2, Inhibits Endothelium-Derived Hyperpolarization–Type Relaxation in Coronary Artery and Produces Bradycardia In Vivo

    PubMed Central

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M.; Laría, Celia; Divina Murillo, María; Gálvez, José A.; Díaz-de-Villegas, María D.; Wulff, Heike; Badorrey, Ramón

    2015-01-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca2+/calmodulin regulated K+ channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca2+ activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K+ channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)–type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1−/− mice. In conclusion, we identified the KCa2/3–negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  15. A novel pan-negative-gating modulator of KCa2/3 channels, fluoro-di-benzoate, RA-2, inhibits endothelium-derived hyperpolarization-type relaxation in coronary artery and produces bradycardia in vivo.

    PubMed

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M; Laría, Celia; Murillo, María Divina; Gálvez, José A; Díaz-de-Villegas, María D; Wulff, Heike; Badorrey, Ramón; Köhler, Ralf

    2015-02-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca(2+)/calmodulin regulated K(+) channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca(2+) activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K(+) channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)-type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1(-/-) mice. In conclusion, we identified the KCa2/3-negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  16. A novel pan-negative-gating modulator of KCa2/3 channels, fluoro-di-benzoate, RA-2, inhibits endothelium-derived hyperpolarization-type relaxation in coronary artery and produces bradycardia in vivo.

    PubMed

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M; Laría, Celia; Murillo, María Divina; Gálvez, José A; Díaz-de-Villegas, María D; Wulff, Heike; Badorrey, Ramón; Köhler, Ralf

    2015-02-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca(2+)/calmodulin regulated K(+) channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca(2+) activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K(+) channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)-type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1(-/-) mice. In conclusion, we identified the KCa2/3-negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  17. Lobaric Acid Inhibits VCAM-1 Expression in TNF-α-Stimulated Vascular Smooth Muscle Cells via Modulation of NF-κB and MAPK Signaling Pathways

    PubMed Central

    Kwon, Ii-Seul; Yim, Joung-Han; Lee, Hong-Kum; Pyo, Suhkneung

    2016-01-01

    Lichens have been known to possess multiple biological activities, including anti-proliferative and anti-inflammatory activities. Vascular cell adhesion molecule-1 (VCAM-1) may play a role in the development of atherosclerosis. Hence, VCAM-1 is a possible therapeutic target in the treatment of the inflammatory disease. However, the effect of lobaric acid on VCAM-1 has not yet been investigated and characterized. For this study, we examined the effect of lobaric acid on the inhibition of VCAM-1 in tumor necrosis factor-alpha (TNF-α)-stimulated mouse vascular smooth muscle cells. Western blot and ELISA showed that the increased expression of VCAM-1 by TNF-α was significantly suppressed by the pre-treatment of lobaric acid (0.1–10 μg/ml) for 2 h. Lobaric acid abrogated TNF-α-induced NF-κB activity through preventing the degradation of IκB and phosphorylation of extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and p38 mitogen activated protein (MAP) kinase. Lobaric acid also inhibited the expression of TNF-α receptor 1 (TNF-R1). Overall, our results suggest that lobaric acid inhibited VCAM-1 expression through the inhibition of p38, ERK, JNK and NF-κB signaling pathways, and downregulation of TNF-R1 expression. Therefore, it is implicated that lobaric acid may suppress inflammation by altering the physiology of the atherosclerotic lesion. PMID:26759698

  18. The personality trait of behavioral inhibition modulates perceptions of moral character and performance during the trust game: behavioral results and computational modeling

    PubMed Central

    Sanchez, Rosanna; Weinflash, Noah; Myers, Catherine E.

    2016-01-01

    Decisions based on trust are critical for human social interaction. We judge the trustworthiness of partners in social interactions based on a number of partner characteristics as well as experiences with those partners. These decisions are also influenced by personality. The current study examined how the personality trait of behavioral inhibition, which involves the tendency to avoid or withdraw from novelty in both social and non-social situations, is related to explicit ratings of trustworthiness as well as decisions made in the trust game. In the game, healthy young adults interacted with three fictional partners who were portrayed as trustworthy, untrustworthy or neutral through biographical information. Participants could choose to keep $1 or send $3 of virtual money to a partner. The partner could then choose to send $1.5 back to the participant or to keep the entire amount. On any trial in which the participant chose to send, the partner always reciprocated with 50% probability, irrespective of how that partner was portrayed in the biography. Behavioral inhibition was assessed through a self-report questionnaire. Finally, a reinforcement learning computational model was fit to the behavior of each participant. Self-reported ratings of trust confirmed that all participants, irrespective of behavioral inhibition, perceived differences in the moral character of the three partners (trustworthiness of good > neutral > bad partner). Decisions made in the game showed that inhibited participants tended to trust the neutral partner less than uninhibited participants. In contrast, this was not reflected in the ratings of the neutral partner (either pre- or post-game), indicating a dissociation between ratings of trustworthiness and decisions made by inhibited participants. Computational modeling showed that this was due to lower initial trust of the neutral partner rather than a higher learning rate associated with loss, suggesting an implicit bias against the

  19. Effect of PDE5 inhibition on the modulation of sympathetic α-adrenergic vasoconstriction in contracting skeletal muscle of young and older recreationally active humans.

    PubMed

    Nyberg, Michael; Piil, Peter; Egelund, Jon; Sprague, Randy S; Mortensen, Stefan P; Hellsten, Ylva

    2015-12-01

    Aging is associated with an altered regulation of blood flow to contracting skeletal muscle; however, the precise mechanisms remain unclear. We recently demonstrated that inhibition of cGMP-binding phosphodiesterase 5 (PDE5) increased blood flow to contracting skeletal muscle of older but not young human subjects. Here we examined whether this effect of PDE5 inhibition was related to an improved ability to blunt α-adrenergic vasoconstriction (functional sympatholysis) and/or improved efficacy of local vasodilator pathways. A group of young (23 ± 1 yr) and a group of older (72 ± 1 yr) male subjects performed knee-extensor exercise in a control setting and following intake of the highly selective PDE5 inhibitor sildenafil. During both conditions, exercise was performed without and with arterial tyramine infusion to evoke endogenous norepinephrine release and consequently stimulation of α1- and α2-adrenergic receptors. The level of the sympatholytic compound ATP was measured in venous plasma by use of the microdialysis technique. Sildenafil increased (P < 0.05) vascular conductance during exercise in the older group, but tyramine infusion reduced (P < 0.05) this effect by 38 ± 9%. Similarly, tyramine reduced (P < 0.05) the vasodilation induced by arterial infusion of a nitric oxide (NO) donor by 54 ± 9% in the older group, and this effect was not altered by sildenafil. Venous plasma [ATP] did not change with PDE5 inhibition in the older subjects during exercise. Collectively, PDE5 inhibition in older humans was not associated with an improved ability for functional sympatholysis. An improved efficacy of the NO system may be one mechanism underlying the effect of PDE5 inhibition on exercise hyperemia in aging.

  20. Cystone – An ayurvedic polyherbal formulation inhibits adherence of uropathogenic E. coli and modulates H2O2-induced toxicity in NRK-52E cells

    PubMed Central

    Vidyashankar, Satyakumar; Maheshkumar, Puttanarasaiah; Patki, Pralhad S

    2010-01-01

    Gentamicin is a widely used antibiotic for the treatment of adverse urinary tract infections (UTI), which in turn causes nephrotoxicity to uroepithelial cells and hence an alternative safe herbal remedy is much desired to compensate these toxic effects. The bacterial adhesion to the uroepithelial cells is the primary step in UTI and it induces various immunogenic reactions leading to the generation of reactive oxygen species (ROS), which are detrimental to the cells survival. Inhibition of bacterial adherence to urinary tract epithelial cells has been assumed to account for the beneficial action ascribed to cystone (an ayurvedic polyherbal formulation) in the prevention of UTI. In this study, we have examined the effect of cystone on the adherence of pathogenic [2-14C]-acetate labeled Escherichia coli (MTCC-729) to rat proximal renal tubular cells (NRK-52E cells). Further, the antioxidant property of cystone was studied using hydrogen peroxide (400 μM) as a pro-oxidant in NRK-52E cells. The results showed that cystone inhibited the adherence of E. coli to NRK-52E cells significantly. Additionally cystone effectively combats the toxicity induced by H2O2 in NRK-52E cells. The cytoprotective effect of cystone is brought about by inhibiting lipid peroxidation by 36% in cells treated with cystone compared to H2O2-treated cells without cystone. The antioxidant enzymes catalase, glutathione were increased by 53% and 68% respectively and superoxide dismutase activity was increased 3-fold. The glutathione content was significantly increased by 2.4-fold in NRK-52E cells treated with cystone compared to H2O2 control group. These results suggest that cystone effectively inhibits bacterial adherence to NRK-52E cells and attenuates H2O2-induced toxicity in NRK-52E cells by inhibiting lipid peroxidation and increasing the antioxidant defense mechanism. PMID:27186087

  1. Cystone - An ayurvedic polyherbal formulation inhibits adherence of uropathogenic E. coli and modulates H2O2-induced toxicity in NRK-52E cells.

    PubMed

    Vidyashankar, Satyakumar; Maheshkumar, Puttanarasaiah; Patki, Pralhad S

    2010-01-01

    Gentamicin is a widely used antibiotic for the treatment of adverse urinary tract infections (UTI), which in turn causes nephrotoxicity to uroepithelial cells and hence an alternative safe herbal remedy is much desired to compensate these toxic effects. The bacterial adhesion to the uroepithelial cells is the primary step in UTI and it induces various immunogenic reactions leading to the generation of reactive oxygen species (ROS), which are detrimental to the cells survival. Inhibition of bacterial adherence to urinary tract epithelial cells has been assumed to account for the beneficial action ascribed to cystone (an ayurvedic polyherbal formulation) in the prevention of UTI. In this study, we have examined the effect of cystone on the adherence of pathogenic [2-(14)C]-acetate labeled Escherichia coli (MTCC-729) to rat proximal renal tubular cells (NRK-52E cells). Further, the antioxidant property of cystone was studied using hydrogen peroxide (400 μM) as a pro-oxidant in NRK-52E cells. The results showed that cystone inhibited the adherence of E. coli to NRK-52E cells significantly. Additionally cystone effectively combats the toxicity induced by H2O2 in NRK-52E cells. The cytoprotective effect of cystone is brought about by inhibiting lipid peroxidation by 36% in cells treated with cystone compared to H2O2-treated cells without cystone. The antioxidant enzymes catalase, glutathione were increased by 53% and 68% respectively and superoxide dismutase activity was increased 3-fold. The glutathione content was significantly increased by 2.4-fold in NRK-52E cells treated with cystone compared to H2O2 control group. These results suggest that cystone effectively inhibits bacterial adherence to NRK-52E cells and attenuates H2O2-induced toxicity in NRK-52E cells by inhibiting lipid peroxidation and increasing the antioxidant defense mechanism.

  2. Inhibition of NF-κB activity in the hypothalamic paraventricular nucleus attenuates hypertension and cardiac hypertrophy by modulating cytokines and attenuating oxidative stress

    SciTech Connect

    Yu, Xiao-Jing; Zhang, Dong-Mei; Jia, Lin-Lin; Qi, Jie; Song, Xin-Ai; Tan, Hong; Cui, Wei; Chen, Wensheng; Zhu, Guo-Qing; Qin, Da-Nian; Kang, Yu-Ming

    2015-05-01

    We hypothesized that chronic inhibition of NF-κB activity in the hypothalamic paraventricular nucleus (PVN) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs), attenuating nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase in the PVN of young spontaneously hypertensive rats (SHR). Young normotensive Wistar–Kyoto (WKY) and SHR rats received bilateral PVN infusions with NF–κB inhibitor pyrrolidine dithiocarbamate (PDTC) or vehicle for 4 weeks. SHR rats had higher mean arterial pressure and cardiac hypertrophy as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, cardiomyocyte diameters of the left cardiac ventricle, and mRNA expressions of cardiac atrial natriuretic peptide (ANP) and beta-myosin heavy chain (β-MHC). These SHR rats had higher PVN levels of proinflammatory cytokines (PICs), reactive oxygen species (ROS), the chemokine monocyte chemoattractant protein-1 (MCP-1), NAD(P)H oxidase activity, mRNA expression of NOX-2 and NOX-4, and lower PVN IL-10, and higher plasma levels of PICs and NE, and lower plasma IL-10. PVN infusion of NF-κB inhibitor PDTC attenuated all these changes. These findings suggest that NF-κB activation in the PVN increases sympathoexcitation and hypertensive response, which are associated with the increases of PICs and oxidative stress in the PVN; PVN inhibition of NF-κB activity attenuates PICs and oxidative stress in the PVN, thereby attenuates hypertension and cardiac hypertrophy. - Highlights: • Spontaneously hypertensive rats exhibit neurohormonal excitation in the PVN. • PVN inhibition of NF-κB attenuates hypertension-induced cardiac hypertrophy. • PVN inhibition of NF-κB attenuates hypertension-induced neurohormonal excitation. • PVN inhibition of NF-κB attenuates hypertension-induced imbalance of cytokines

  3. Quince (Cydonia oblonga Miller) peel polyphenols modulate LPS-induced inflammation in human THP-1-derived macrophages through NF-{kappa}B, p38MAPK and Akt inhibition

    SciTech Connect

    Essafi-Benkhadir, Khadija; Refai, Amira; Riahi, Ichrak; Fattouch, Sami; Karoui, Habib; Essafi, Makram

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Quince peel polyphenols inhibit LPS-induced secretion of TNF-{alpha} and IL-8. Black-Right-Pointing-Pointer Quince peel polyphenols augment LPS-induced secretion of IL-10 and IL-6. Black-Right-Pointing-Pointer Quince peel polyphenols-mediated inhibition of LPS-induced secretion of TNF-{alpha} is partially mediated by IL-6. Black-Right-Pointing-Pointer The anti-inflammatory effects of quince polyphenols pass through NF-{kappa}B, p38MAPK and Akt inhibition. -- Abstract: Chronic inflammation is a hallmark of several pathologies, such as rheumatoid arthritis, gastritis, inflammatory bowel disease, atherosclerosis and cancer. A wide range of anti-inflammatory chemicals have been used to treat such diseases while presenting high toxicity and numerous side effects. Here, we report the anti-inflammatory effect of a non-toxic, cost-effective natural agent, polyphenolic extract from the Tunisian quince Cydonia oblonga Miller. Lipopolysaccharide (LPS) treatment of human THP-1-derived macrophages induced the secretion of high levels of the pro-inflammatory cytokine TNF-{alpha} and the chemokine IL-8, which was inhibited by quince peel polyphenolic extract in a dose-dependent manner. Concomitantly, quince polyphenols enhanced the level of the anti-inflammatory cytokine IL-10 secreted by LPS-treated macrophages. We further demonstrated that the unexpected increase in IL-6 secretion that occurred when quince polyphenols were associated with LPS treatment was partially responsible for the polyphenols-mediated inhibition of TNF-{alpha} secretion. Biochemical analysis showed that quince polyphenols extract inhibited the LPS-mediated activation of three major cellular pro-inflammatory effectors, nuclear factor-kappa B (NF-{kappa}B), p38MAPK and Akt. Overall, our data indicate that quince peel polyphenolic extract induces a potent anti-inflammatory effect that may prove useful for the treatment of inflammatory diseases and that a quince

  4. Synthesis and alkylation of Aza-Gly-Pro building blocks of peptidomimetic libraries for developing prostaglandin F2α receptor modulators as therapeutics to inhibit preterm labor.

    PubMed

    Bourguet, Carine B; Lubell, William D

    2015-01-01

    Premature birth is a steadily increasing unmet medical need, for which new "tocolytic" agents are required to arrest contractions and delay labor. A peptide-based approach was developed to produce modulators of the prostaglandin F2α receptor as a novel target for tocolytic development. In this strategy, the solution-phase synthesis and alkylation of aza-glycyl-proline building blocks were key for the preparation of a series of modulators exhibiting biased signaling. An optimized method is now provided for making the aza-Gly-Pro unit with minimum side product, and alkylation of the unit is described to illustrate the library diversification step. Conditions have been reported for selectively unmasking the protecting groups at the N- and C-terminal of the aza-dipeptide unit and for its introduction into analogs that modulate the signaling of the PGF2α receptor. The merits of this protocol for azapeptide synthesis have thus been demonstrated by the synthesis of inhibitors of myometrial contraction exhibiting potential as prototypes for developing tocolytics to treat preterm labor. PMID:25616327

  5. Modulation of Spc1 stress-activated protein kinase activity by methylglyoxal through inhibition of protein phosphatase in the fission yeast Schizosaccharomyces pombe

    SciTech Connect

    Takatsume, Yoshifumi; Izawa, Shingo; Inoue, Yoshiharu

    2007-11-30

    Methylglyoxal, a ubiquitous metabolite derived from glycolysis has diverse physiological functions in yeast cells. Previously, we have reported that extracellularly added methylglyoxal activates Spc1, a stress-activated protein kinase (SAPK), in the fission yeast Schizosaccharomyces pombe [Y. Takatsume, S. Izawa, Y. Inoue, J. Biol. Chem. 281 (2006) 9086-9092]. Phosphorylation of Spc1 by treatment with methylglyoxal in S. pombe cells defective in glyoxalase I, an enzyme crucial for the metabolism of methylglyoxal, continues for a longer period than in wild-type cells. Here we show that methylglyoxal inhibits the activity of the protein phosphatase responsible for the dephosphorylation of Spc1 in vitro. In addition, we found that methylglyoxal inhibits human protein tyrosine phosphatase 1B (PTP1B) also. We propose a model for the regulation of the activity of the Spc1-SAPK signaling pathway by methylglyoxal in S. pombe.

  6. Potentiation of growth inhibition and epigenetic modulation by combination of green tea polyphenol and 5-aza-2'-deoxycytidine in human breast cancer cells.

    PubMed

    Tyagi, Tulika; Treas, Justin N; Mahalingaiah, Prathap Kumar S; Singh, Kamaleshwar P

    2015-02-01

    Epigenetic therapy by DNA demethylating agent 5-aza-2'-deoxycytidine (5-aza 2'dC) is clinically effective in acute myeloid leukemia; however, it has shown limited results in treatment of breast cancer and has significant toxicity to normal cells. Green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) has anti-cancer and DNA demethylating properties with no significant toxicity toward normal cells. Therefore, the objective of this study was to evaluate the therapeutic efficacy of a combination of non-toxic, low dose of 5-aza 2' dC with EGCG, on growth inhibition of breast cancer cells. Human breast cancer cell lines (MCF-7, MDA-MB 231) and non-tumorigenic MCF-10A breast epithelial cells were treated with either 5-aza 2' dC, EGCG, or their combination for 7 days. Cell growth inhibition was determined by cell count, cell viability, cell cycle, and soft agar assay, whereas genes expression changes were determined by quantitative real-time PCR and/or Western blot analysis. Histone modifications and global DNA methylation changes were determined by Western blot and RAPD-PCR, respectively. The results revealed significantly greater inhibition of growth of breast cancer cells by co-treatment with 5-aza 2' dC and EGCG compared to individual treatments, whereas it has no significant toxicity to MCF-10A cells. This was further confirmed by gene expression analysis. Changes in DNA methylation and histone modifications were also greater in cells with combination treatment. Findings of this study suggest that potentiation of growth inhibition of breast cancer cells by 5-aza 2' dC and EGCG combination treatment, at least in part, is mediated by epigenetic mechanism.

  7. Polydatin (PD) inhibits IgE-mediated passive cutaneous anaphylaxis in mice by stabilizing mast cells through modulating Ca{sup 2+} mobilization

    SciTech Connect

    Yuan, Meichun; Li, Jianjie; Lv, Jingzhang; Mo, Xucheng; Yang, Chengbin; Chen, Xiangdong; Liu, Zhigang; Liu, Jie

    2012-11-01

    Mast cells play a key role in the pathogenesis of asthma and are a promising target for therapeutic intervention in asthma. This study investigated the effects of polydatin (PD), a resveratrol glucoside, on mast cell degranulation upon cross-linking of the high-affinity IgE receptors (FcεRI), as well as the anti-allergic activity of PD in vivo. Herein, we demonstrated that PD treatment for 30 min suppressed FcεRI-mediated mast cell degranulation in a dose-dependent manner. Concomitantly, PD significantly decreased FcεRI-mediated Ca{sup 2+} increase in mast cells. The suppressive effects of PD on FcεRI-mediated Ca{sup 2+} increase were largely inhibited by using LaCl{sub 3} to block the Ca{sup 2+} release-activated Ca{sup 2+} channels (CRACs). Furthermore, PD significantly inhibited Ca{sup 2+} entry through CRACs evoked by thapsigargin (TG). Knocking down protein expression of Orai1, the pore-forming subunit of CRACs, significantly decreased PD suppression of FcεRI-induced intracellular Ca{sup 2+} influx and mast cell degranulation. In a mouse model of mast cell-dependent passive cutaneous anaphylaxis (PCA), in vivo PD administration suppressed mast cell degranulation and inhibited anaphylaxis. Taken together, our data indicate that PD stabilizes mast cells by suppressing FcεRI-induced Ca{sup 2+} mobilization mainly through inhibiting Ca{sup 2+} entry via CRACs, thus exerting a protective effect against PCA. -- Highlights: ► Polydatin can prevent the pathogenesis of passive cutaneous anaphylaxis in mice. ► Polydatin stabilizes mast cells by decreasing FcεRI-mediated degranulation. ► Polydatin suppresses Ca{sup 2+} entry through CRAC channels in mast cells.

  8. 4-Coumaroyl and caffeoyl shikimic acids inhibit 4-coumaric acid:coenzyme A ligases and modulate metabolic flux for 3-hydroxylation in monolignol biosynthesis of Populus trichocarpa.

    PubMed

    Lin, Chien-Yuan; Wang, Jack P; Li, Quanzi; Chen, Hsi-Chuan; Liu, Jie; Loziuk, Philip; Song, Jina; Williams, Cranos; Muddiman, David C; Sederoff, Ronald R; Chiang, Vincent L

    2015-01-01

    Downregulation of 4-coumaric acid:coenzyme A ligase (4CL) can reduce lignin content in a number of plant species. In lignin precursor (monolignol) biosynthesis during stem wood formation in Populus trichocarpa, two enzymes, Ptr4CL3 and Ptr4CL5, catalyze the coenzyme A (CoA) ligation of 4-coumaric acid to 4-coumaroyl-CoA and caffeic acid to caffeoyl-CoA. CoA ligation of 4-coumaric acid is essential for the 3-hydroxylation of 4-coumaroyl shikimic acid. This hydroxylation results from sequential reactions of 4-hydroxycinnamoyl-CoA:shikimic acid hydroxycinnamoyl transferases (PtrHCT1 and PtrHCT6) and 4-coumaric acid 3-hydroxylase 3 (PtrC3H3). Alternatively, 3-hydroxylation of 4-coumaric acid to caffeic acid may occur through an enzyme complex of cinnamic acid 4-hydroxylase 1 and 2 (PtrC4H1 and PtrC4H2) and PtrC3H3. We found that 4-coumaroyl and caffeoyl shikimic acids are inhibitors of Ptr4CL3 and Ptr4CL5. 4-Coumaroyl shikimic acid strongly inhibits the formation of 4-coumaroyl-CoA and caffeoyl-CoA. Caffeoyl shikimic acid inhibits only the formation of 4-coumaroyl-CoA. 4-Coumaroyl and caffeoyl shikimic acids both act as competitive and uncompetitive inhibitors. Metabolic flux in wild-type and PtrC3H3 downregulated P. trichocarpa transgenics has been estimated by absolute protein and metabolite quantification based on liquid chromatography-tandem mass spectrometry, mass action kinetics, and inhibition equations. Inhibition by 4-coumaroyl and caffeoyl shikimic acids may play significant regulatory roles when these inhibitors accumulate.

  9. Piceatannol, Natural Polyphenolic Stilbene, Inhibits Adipogenesis via Modulation of Mitotic Clonal Expansion and Insulin Receptor-dependent Insulin Signaling in Early Phase of Differentiation*

    PubMed Central

    Kwon, Jung Yeon; Seo, Sang Gwon; Heo, Yong-Seok; Yue, Shuhua; Cheng, Ji-Xin; Lee, Ki Won; Kim, Kee-Hong

    2012-01-01

    Piceatannol, a natural stilbene, is an analog and a metabolite of resveratrol. Despite a well documented health benefit of resveratrol in intervention of the development of obesity, the role of piceatannol in the development of adipose tissue and related diseases is unknown. Here, we sought to determine the function of piceatannol in adipogenesis and elucidate the underlying mechanism. We show that piceatannol inhibits adipogenesis of 3T3-L1 preadipocytes in a dose-dependent manner at noncytotoxic concentrations. This anti-adipogenic property of piceatannol was largely limited to the early event of adipogenesis. In the early phase of adipogenesis, piceatannol-treated preadipocytes displayed a delayed cell cycle entry into G2/M phase at 24 h after initiation of adipogenesis. Furthermore, the piceatannol-suppressed mitotic clonal expansion was accompanied by reduced activation of the insulin-signaling pathway. Piceatannol dose-dependently inhibited differentiation mixture-induced phosphorylation of insulin receptor (IR)/insulin receptor substrate-1 (IRS-1)/Akt pathway in the early phase of adipogenesis. Moreover, we showed that piceatannol is an inhibitor of IR kinase activity and phosphatidylinositol 3-kinase (PI3K). Our kinetics study of IR further identified a Km value for ATP of 57.8 μm and a Ki value for piceatannol of 28.9 μm. We also showed that piceatannol directly binds to IR and inhibits IR kinase activity in a mixed noncompetitive manner to ATP, through which piceatannol appears to inhibit adipogenesis. Taken together, our study reveals an anti-adipogenic function of piceatannol and highlights IR and its downstream insulin signaling as novel targets for piceatannol in the early phase of adipogenesis. PMID:22298784

  10. Pure enantiomers of benzoylamino-tranylcypromine: LSD1 inhibition, gene modulation in human leukemia cells and effects on clonogenic potential of murine promyelocytic blasts.

    PubMed

    Valente, Sergio; Rodriguez, Veronica; Mercurio, Ciro; Vianello, Paola; Saponara, Bruna; Cirilli, Roberto; Ciossani, Giuseppe; Labella, Donatella; Marrocco, Biagina; Monaldi, Daria; Ruoppolo, Giovanni; Tilset, Mats; Botrugno, Oronza A; Dessanti, Paola; Minucci, Saverio; Mattevi, Andrea; Varasi, Mario; Mai, Antonello

    2015-04-13

    The pure enantiomers of the N-(2-, 3-, and 4-(2-aminocyclopropyl)phenyl)benzamides hydrochlorides 11a-j were prepared and tested against LSD1 and MAO enzymes. The evaluation of the regioisomers 11a-j highlighted a net increase of the anti-LSD1 potency by shifting the benzamide moiety from ortho to meta and mainly to para position of tranylcypromine phenyl ring, independently from their trans or cis stereochemistry. In particular, the para-substituted 11a,b (trans) and 11g,h (cis) compounds displayed LSD1 and MAO-A inhibition at low nanomolar levels, while were less potent against MAO-B. The meta analogs 11c,d (trans) and 11i,j (cis) were in general less potent, but more efficient against MAO-A than against LSD1. In cellular assays, all the para and meta enantiomers were able to inhibit LSD1 by inducing Gfi-1b and ITGAM gene expression, with 11b,c and 11g-i giving the highest effects. Moreover, 11b and 11g,h strongly inhibited the clonogenic potential of murine promyelocytic blasts. PMID:25768700

  11. Inhibition of hydrogen sulfide on the proliferation of vascular smooth muscle cells involved in the modulation of calcium sensing receptor in high homocysteine.

    PubMed

    Wang, Yuwen; Wang, Xiyao; Liang, Xiaohui; Wu, Jichao; Dong, Shiyun; Li, Hongzhu; Jin, Meili; Sun, Dianjun; Zhang, Weihua; Zhong, Xin

    2016-09-10

    Hyperhomocysteinemia induces the proliferation of vascular smooth muscle cells (VSMCs). Hydrogen sulfide (H2S) inhibits the phenotype switch of VSMCs and calcium-sensing receptor (CaSR) regulated the production of endogenous H2S. However, whether CaSR inhibits the proliferation of VSMCs by regulating the endogenous cystathionine-gamma-lyase (CSE, a major enzyme that produces H2S) pathway in high homocysteine (HHcy) has not been previously investigated. The intracellular calcium concentration, the concentration of H2S, the cell viability, the proliferation and the expression of proteins of cultured VSMCs from rat thoracic aortas were measured, respectively. The results showed that the [Ca(2+)]i and the expression of p-CaMK and CSE increased upon treatment with CaSR agonist. In HHcy, the H2S concentration decrease, the proliferation and migration rate increased, the expression of Cyclin D1, PCNA, Osteopontin and p-Erk1/2 increased while the α-SM actin, P21(Cip/WAK-1) and Calponin decreased. The CaSR agonist or exogenous H2S significantly reversed the changes of VSMCs caused by HHcy. In conclusion, our results demonstrated that CaSR regulate the endogenous CSE/H2S is related to the PLC-IP3 receptor and CaM signal pathways which inhibit the proliferation of VSMCs, and the latter is involved in the Erk1/2 dependent signal pathway in high homocysteine. PMID:27502588

  12. Cellular thiol status-dependent inhibition of tumor cell growth via modulation of p27(kip1) translocation and retinoblastoma protein phosphorylation by 1'-acetoxychavicol acetate.

    PubMed

    Unahara, Y; Kojima-Yuasa, A; Higashida, M; Kennedy, D O; Murakami, A; Ohigashi, H; Matsui-Yuasa, I

    2007-09-01

    1'-Acetoxychavicol acetate (ACA) has been shown to inhibit tumor cell growth, but there is limited information on its effects on cell signaling and the cell cycle control pathway. In this study, we sought to determine how ACA alters cell cycle and its related control factors in its growth inhibitory effect in Ehrlich ascites tumor cells (EATC). ACA caused an accumulation of cells in the G1 phase and an inhibition of DNA synthesis, which were reversed by supplementation with N-acetylcysteine (NAC) or glutathione ethyl ester (GEE). Furthermore, ACA decreased hyperphosphorylated Rb levels and increased hypophosphorylated Rb levels. NAC and GEE also abolished the decease in Rb phosphorylation by ACA. As Rb phosphorylation is regulated by G1 cyclin dependent kinase and CDK inhibitor p27(kip1), which is an important regulator of the mammalian cell cycle, we estimated the amount of p27(kip1) levels by western blotting. Treatment with ACA had virtually no effect on the amount of p27(kip1) levels, but caused a decrease in phosphorylated p27(kip1) and an increase in unphosphorylated p27(kip1) as well as an increase in the nuclear localization of p27(kip1). These events were abolished in the presence of NAC or GEE. These results suggest that in EATC, cell growth inhibition elicited by ACA involves decreases in Rb and p27(kip1) phosphorylation and an increase in nuclear localization of p27(kip1), and these events are dependent on the cellular thiol status.

  13. Delphinidin inhibits IL-1β-induced activation of NF-κB by modulating the phosphorylation of IRAK-1Ser376 in human articular chondrocytes

    PubMed Central

    Haseeb, Abdul; Chen, Dongxing

    2013-01-01

    Objective. In OA, there is enhanced expression of pro-inflammatory cytokines such as IL-1β in the affected joint. Delphinidin, an anthocyanidin found in pigmented fruits and vegetables, has been shown to possess anti-inflammatory and antioxidant properties. In the present study we determined whether delphinidin would inhibit the IL-1β-induced activation of NF-κB in human chondrocytes and determined the mechanism of its action. Methods. PGE2 levels and activation of NF-κB p65 in human OA chondrocytes were determined by ELISA-based assays. Protein expression of cyclo-oxygenase-2 (COX-2) and phosphorylation of kinases was determined by western immunoblotting. Expression level of mRNAs was determined by TaqMan assays. Results. Delphinidin inhibited IL-1β-induced expression of COX-2 and production of PGE2 in human chondrocytes. Delphinidin also inhibited IL-1β-mediated phosphorylation of IL-1 receptor-associated kinase-1Ser376, phosphorylation of IKKα/β, expression of IKKβ, degradation of IκBα, and activation and nuclear translocation of NF-κB/p65. Phosphorylation of TGF-β-activated kinase 1 was not observed but NF-κB-inducing kinase (NIK) was phosphorylated and phosphorylation of NIK was blocked by delphinidin in IL-1β-treated human chondrocytes. Conclusion. These data identify delphinidin as a novel inhibitor of IL-1β-induced production of cartilage-degrading molecule PGE2 via inhibition of COX-2 expression and provide new insight into the mechanism of its action. Our results also identify inhibition of IRAK1Ser376 phosphorylation by delphinidin in IL-1β-induced activation of NF-κB in human chondrocytes. Given the important role played by IL-1β-induced NF-κB activation, COX-2 expression and PGE2 production in OA, our results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA. PMID:23392593

  14. Allosteric modulation of an excitatory amino acid transporter: the subtype-selective inhibitor UCPH-101 exerts sustained inhibition of EAAT1 through an intramonomeric site in the trimerization domain.

    PubMed

    Abrahamsen, Bjarke; Schneider, Nicole; Erichsen, Mette N; Huynh, Tri H V; Fahlke, Christoph; Bunch, Lennart; Jensen, Anders A

    2013-01-16

    In the present study, the mechanism of action and molecular basis for the activity of the first class of selective inhibitors of the human excitatory amino acid transporter subtype 1 (EAAT1) and its rodent ortholog GLAST are elucidated. The previously reported specificity of UCPH-101 and UCPH-102 for EAAT1 over EAAT2 and EAAT3 is demonstrated to extend to the EAAT4 and EAAT5 subtypes as well. Interestingly, brief exposure to UCPH-101 induces a long-lasting inactive state of EAAT1, whereas the inhibition exerted by closely related analogs is substantially more reversible in nature. In agreement with this, the kinetic properties of UCPH-101 unblocking of the transporter are considerably slower than those of UCPH-102. UCPH-101 exhibits noncompetitive inhibition of EAAT1, and its binding site in GLAST has been delineated in an elaborate mutagenesis study. Substitutions of several residues in TM3, TM4c, and TM7a of GLAST have detrimental effects on the inhibitory potency and/or efficacy of UCPH-101 while not affecting the pharmacological properties of (S)-glutamate or the competitive EAAT inhibitor TBOA significantly. Hence, UCPH-101 is proposed to target a predominantly hydrophobic crevice in the "trimerization domain" of the GLAST monomer, and the inhibitor is demonstrated to inhibit the uptake through the monomer that it binds to exclusively and not to affect substrate translocation through the other monomers in the GLAST trimer. The allosteric mode of UCPH-101 inhibition underlines the functional importance of the trimerization domain of the EAAT and demonstrates the feasibility of modulating transporter function through ligand binding to regions distant from its "transport domain." PMID:23325245

  15. p53-Independent Inhibition of Proliferation and p21Waf1/Cip1-Modulated Induction of Cell Death by the Antioxidants N-acetylcysteine and Vitamin E1

    PubMed Central

    Nargi, Jennifer L; Ratan, Rajiv R; Griffin, Diane E

    1999-01-01

    Abstract Epidemiological evidence has suggested an association between diets rich in antioxidants and diminished risks of various types of cancer. Proposed mechanisms for protective effects of antioxidants have involved inhibition of free radical-mediated DNA damage. Recent data suggest that antioxidants may prevent or eliminate cancerous cells through their ability to inhibit proliferation or to induce programmed cell death (PCD). To begin to identify cell cycle and cell death regulatory factors involved in antioxidant-induced growth arrest and PCD, we have studied colorectal carcinoma cells (CRCs) that differ in expression of the tumor suppressor protein p53, and of the cyclin-dependent kinase (CDK) inhibitor p21Waf1/Cip1. The antioxidants, N-acetylcysteine (NAC) and vitamin E either inhibited proliferation in a p53-independent manner without affecting cell viability or induced cell death. Growth arrest was not associated with upregulation of the CDK inhibitors p21Waf1/Cip1, p18ink4c or p16ink4a, but was associated with a decrease in reactive oxygen species (ROS). In contrast to previous observations, the absence of p21Waf1/Cip1 increased susceptibility of CRCs to antioxidant-induced PCD. NAC decreased levels of retinoblastoma protein (Rb) phosphorylation in all cells tested, but Rb was cleaved only in cells which underwent NAC-induced death. Although NAC decreased ROS in all cells studied, cell lines in which PCD occurred had higher baseline levels of ROS than cell lines in which proliferation was blocked. These observations suggest that expression of p21Waf1/Cip1 and basal levels of ROS are important determinants of outcome after antioxidant treatment. PMID:10935502

  16. Modulation of plasminogen activator inhibitor-1 in vivo: a new mechanism for the anti-fibrotic effect of renin-angiotensin inhibition.

    PubMed

    Oikawa, T; Freeman, M; Lo, W; Vaughan, D E; Fogo, A

    1997-01-01

    We examined the potential of in vivo linkage of plasminogen activator inhibitor-1 (PAI-1) and angiotensin II (Ang II) in the setting of endothelial injury and sclerosis following radiation injury in the rat. PAI-1 is a major physiological inhibitor of the plasminogen activator (PA)/plasmin system, a key regulator of fibrinolysis and extracellular matrix (ECM) turnover. PAI-1 mRNA expression in the kidney was markedly increased (9-fold) at 12 weeks after irradiation (P < 1.001 vs. normal control). In situ hybridization revealed significant association of PAI-1 expression with sites of glomerular injury (signal intensity in injured vs. intact glomeruli, P < 0.001). Angiotensin converting enzyme inhibitors (ACEI, captopril or enalapril) or angiotensin II receptor antagonist (AIIRA, L158,809) markedly reduced glomerular lesions (thrombosis, mesangiolysis, and sclerosis; sclerosis index, 0 to 4+ scale, 0.49 +/- 0.20 in untreated vs. 0.05 +/- 0.02, 0.02 +/- 0.01, 0.04 +/- 0.02 in captopril, enalapril and AIIRA, respectively, all P < 0.01 vs untreated). Further, ACEI and AIIRA markedly attenuated increased PAI-1 mRNA expression in the irradiated kidney (36, 19 and 20% expression, respectively, for captopril, enalapril and AIIRA, compared to untreated irradiated kidney, P < 0.05, < 0.01, < 0.01). This effect was selective in that neither tissue-type nor urokinase-type PA mRNA expression was affected by these interventions. Thus, we speculate that inhibition of the renin-angiotensin system may ameliorate injury following radiation by accelerating fibrinolysis and ECM degradation, at least in part, via suppression of PAI-1 expression. In summary, inhibition of Ang II, in addition to its known effects on vascular sclerosis, may also by its novel effect to inhibit PAI-1, lessen fibrosis following endothelial/thrombotic injury.

  17. Surfactant Protein D Inhibits HIV-1 Infection of Target Cells via Interference with gp120-CD4 Interaction and Modulates Pro-Inflammatory Cytokine Production

    PubMed Central

    Pandit, Hrishikesh; Gopal, Sandhya; Sonawani, Archana; Yadav, Ajit Kumar; Qaseem, Asif S.; Warke, Himangi; Patil, Anushree; Gajbhiye, Rahul; Kulkarni, Vijay; Al-Mozaini, Maha Ahmed; Idicula-Thomas, Susan; Kishore, Uday; Madan, Taruna

    2014-01-01

    Surfactant Protein SP-D, a member of the collectin family, is a pattern recognition protein, secreted by mucosal epithelial cells and has an important role in innate immunity against various pathogens. In this study, we confirm that native human SP-D and a recombinant fragment of human SP-D (rhSP-D) bind to gp120 of HIV-1 and significantly inhibit viral replication in vitro in a calcium and dose-dependent manner. We show, for the first time, that SP-D and rhSP-D act as potent inhibitors of HIV-1 entry in to target cells and block the interaction between CD4 and gp120 in a dose-dependent manner. The rhSP-D-mediated inhibition of viral replication was examined using three clinical isolates of HIV-1 and three target cells: Jurkat T cells, U937 monocytic cells and PBMCs. HIV-1 induced cytokine storm in the three target cells was significantly suppressed by rhSP-D. Phosphorylation of key kinases p38, Erk1/2 and AKT, which contribute to HIV-1 induced immune activation, was significantly reduced in vitro in the presence of rhSP-D. Notably, anti-HIV-1 activity of rhSP-D was retained in the presence of biological fluids such as cervico-vaginal lavage and seminal plasma. Our study illustrates the multi-faceted role of human SP-D against HIV-1 and potential of rhSP-D for immunotherapy to inhibit viral entry and immune activation in acute HIV infection. PMID:25036364

  18. αE-catenin inhibits a Src-YAP1 oncogenic module that couples tyrosine kinases and the effector of Hippo signaling pathway.

    PubMed

    Li, Peng; Silvis, Mark R; Honaker, Yuchi; Lien, Wen-Hui; Arron, Sarah T; Vasioukhin, Valeri

    2016-04-01

    Cell-cell adhesion protein αE-catenin inhibits skin squamous cell carcinoma (SCC) development; however, the mechanisms responsible for this function are not completely understood. We report here that αE-catenin inhibits β4 integrin-mediated activation of SRC tyrosine kinase.SRCis the first discovered oncogene, but the protein substrate critical for SRC-mediated transformation has not been identified. We found that YAP1, the pivotal effector of the Hippo signaling pathway, is a direct SRC phosphorylation target, and YAP1 phosphorylation at three sites in its transcription activation domain is necessary for SRC-YAP1-mediated transformation. We uncovered a marked increase in this YAP1 phosphorylation in human and mouse SCC tumors with low/negative expression of αE-catenin. We demonstrate that the tumor suppressor function of αE-catenin involves negative regulation of the β4 integrin-SRC signaling pathway and that SRC-mediated phosphorylation and activation of YAP1 are an alternative to the canonical Hippo signaling pathway that directly connect oncogenic tyrosine kinase signaling with YAP1. PMID:27013234

  19. The Cu-Zn superoxide dismutase (SOD1) inhibits ERK phosphorylation by muscarinic receptor modulation in rat pituitary GH3 cells

    SciTech Connect

    Secondo, Agnese; De Mizio, Mariarosaria; Zirpoli, Laura; Santillo, Mariarosaria; Mondola, Paolo

    2008-11-07

    The Cu-Zn superoxide dismutase (SOD1) belongs to a family of isoenzymes that are able to dismutate the oxygen superoxide in hydrogen peroxide and molecular oxygen. This enzyme is secreted by many cellular lines and it is also released trough a calcium-dependent depolarization mechanism involving SNARE protein SNAP 25. Using rat pituitary GH3 cells that express muscarinic receptors we found that SOD1 inhibits P-ERK1/2 pathway trough an interaction with muscarinic M1 receptor. This effect is strengthened by oxotremorine, a muscarinic M agonist and partially reverted by pyrenzepine, an antagonist of M1 receptor; moreover this effect is independent from increased intracellular calcium concentration induced by SOD1. Finally, P-ERK1/2 inhibition was accompanied by the reduction of GH3 cell proliferation. These data indicate that SOD1 beside the well studied antioxidant properties can be considered as a neuromodulator able to affect mitogen-activated protein kinase in rat pituitary cells trough a M1 muscarinic receptor.

  20. Tetramethylpyrazine reduces inflammation in liver fibrosis and inhibits inflammatory cytokine expression in hepatic stellate cells by modulating NLRP3 inflammasome pathway.

    PubMed

    Wu, Xiafei; Zhang, Feng; Xiong, Xin; Lu, Chunfeng; Lian, Naqi; Lu, Yin; Zheng, Shizhong

    2015-04-01

    Hepatic fibrosis is concomitant with liver inflammation, which has been highlighted as significant treatment of chronic liver disease. We previously demonstrated that tetramethylpyrazine (TMP), the effective component of Ligusticum chuanxiong Hort, can inhibit the activation of HSCs and consequential anti-hepatic fibrosis. In this study, our work demonstrated that TMP improved liver histological architecture, decreased hepatic enzyme levels and attenuated collagen deposition in the rat fibrotic liver. In addition, TMP significantly protected the liver from CCl4-caused injury and fibrogenesis by suppressing inflammation with reducing levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), NLRP3, nuclear factor-kappa B (NF-κB) and interleukin-1β (IL-1β). Experiments in vitro showed that TMP inhibited inflammatory cytokine expression in HSCs associated with disrupting platelet-derived growth factor-b receptor (PDGF-βR)/NLRP3/caspase1 pathway. These data collectively indicate that TMP can attenuate liver inflammation in liver fibrosis and possibly by targeting HSCs via PDGF-βR/NLRP3/caspase1 pathway. It provides novel mechanistic insights into TMP as a potential therapeutic remedy for hepatic fibrosis. PMID:25847612

  1. Pyrroloquinoline Quinone Decelerates Rheumatoid Arthritis Progression by Inhibiting Inflammatory Responses and Joint Destruction via Modulating NF-κB and MAPK Pathways.

    PubMed

    Liu, Zhongbing; Sun, Chi; Tao, Ran; Xu, Xinbao; Xu, Libin; Cheng, Hongbing; Wang, Youhua; Zhang, Dongmei

    2016-02-01

    Pyrroloquinoline quinone (PQQ) is a naturally occurring redox cofactor that acts as an essential nutrient and antioxidant and has been reported to exert potent immunosuppressive effects. However, the therapeutically potential of PQQ on rheumatoid arthritis (RA) has not been explored. In the present study, the anti-inflammatory effects of PQQ were investigated in interleukin (IL)-1β-treated SW982 cells, a RA-like fibroblast-like synoviocytes (FLSs) injury model. Our observations showed that pretreatment with PQQ significantly inhibited the expression of matrix metalloproteinase (MMP)-1 and MMP-3 and suppressed the production of proinflammatory mediators such as TNF-α and IL-6 in IL-1β-treated SW982 cells. The nuclear translocation of nuclear factor kappa B (NF-κB) and the phosphorylation level of p65, p38, and JNK MAP kinase pathways were also inhibited by PQQ in IL-1β-stimulated SW982 cells. To further confirm the therapeutic effects of PQQ on RA in vivo, a collagen-induced arthritis (CIA) model was used. Mice treated with PQQ demonstrated marked attenuation of arthritic symptoms based on histopathology and clinical arthritis scores. These results collectively suggested that PQQ might be a promising therapeutic agent for alleviating the progress of RA.

  2. Small Molecule Inhibition of miR-544 Biogenesis Disrupts Adaptive Responses to Hypoxia by Modulating ATM-mTOR Signaling.

    PubMed

    Haga, Christopher L; Velagapudi, Sai Pradeep; Strivelli, Jacqueline R; Yang, Wang-Yong; Disney, Matthew D; Phinney, Donald G

    2015-10-16

    Hypoxia induces a complex circuit of gene expression that drives tumor progression and increases drug resistance. Defining these changes allows for an understanding of how hypoxia alters tumor biology and informs design of lead therapeutics. We probed the role of microRNA-544 (miR-544), which silences mammalian target of rapamycin (mTOR), in a hypoxic breast cancer model by using a small molecule (1) that selectively impedes the microRNA's biogenesis. Application of 1 to hypoxic tumor cells selectively inhibited production of the mature microRNA, sensitized cells to 5-fluorouracil, and derepressed mRNAs affected by miR-544 in cellulo and in vivo, including boosting mTOR expression. Thus, small molecule inhibition of miR-544 reverses a tumor cell's physiological response to hypoxia. Importantly, 1 sensitized tumor cells to hypoxia-associated apoptosis at a 25-fold lower concentration than a 2'-O-methyl RNA antagomir and was as selective. Further, the apoptotic effect of 1 was suppressed by treatment of cell with rapamycin, a well-known inhibitor of the mTOR signaling pathway, illustrating the selectivity of the compound. Thus, RNA-directed chemical probes, which could also serve as lead therapeutics, enable interrogation of complex cellular networks in cells and animals.

  3. 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

  4. 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

  5. Dipeptidyl peptidase-4 inhibition ameliorates Western diet-induced hepatic steatosis and insulin resistance through hepatic lipid remodeling and modulation of hepatic mitochondrial function.

    PubMed

    Aroor, Annayya R; Habibi, Javad; Ford, David A; Nistala, Ravi; Lastra, Guido; Manrique, Camila; Dunham, Merlow M; Ford, Kaitlin D; Thyfault, John P; Parks, Elizabeth J; Sowers, James R; Rector, R Scott

    2015-06-01

    Novel therapies are needed for treating the increasing prevalence of hepatic steatosis in Western populations. In this regard, dipeptidyl peptidase-4 (DPP-4) inhibitors have recently been reported to attenuate the development of hepatic steatosis, but the potential mechanisms remain poorly defined. In the current study, 4-week-old C57Bl/6 mice were fed a high-fat/high-fructose Western diet (WD) or a WD containing the DPP-4 inhibitor, MK0626, for 16 weeks. The DPP-4 inhibitor prevented WD-induced hepatic steatosis and reduced hepatic insulin resistance by enhancing insulin suppression of hepatic glucose output. WD-induced accumulation of hepatic triacylglycerol (TAG) and diacylglycerol (DAG) content was significantly attenuated with DPP-4 inhibitor treatment. In addition, MK0626 significantly reduced mitochondrial incomplete palmitate oxidation and increased indices of pyruvate dehydrogenase activity, TCA cycle flux, and hepatic TAG secretion. Furthermore, DPP-4 inhibition rescued WD-induced decreases in hepatic PGC-1α and CPT-1 mRNA expression and hepatic Sirt1 protein content. Moreover, plasma uric acid levels in mice fed the WD were decreased after MK0626 treatment. These studies suggest that DPP-4 inhibition ameliorates hepatic steatosis and insulin resistance by suppressing hepatic TAG and DAG accumulation through enhanced mitochondrial carbohydrate utilization and hepatic TAG secretion/export with a concomitant reduction of uric acid production.

  6. Marine Compound Catunaregin Inhibits Angiogenesis through the Modulation of Phosphorylation of Akt and eNOS in vivo and in vitro

    PubMed Central

    Liu, Jun-Xiu; Luo, Min-Qi; Xia, Meng; Wu, Qi; Long, Si-Mei; Hu, Yaohua; Gao, Guang-Chun; Yao, Xiao-Li; He, Mian; Su, Huanxing; Luo, Xiong-Ming; Yao, Shu-Zhong

    2014-01-01

    Angiogenesis is the formation of blood vessels from pre-existing vasculature. Excessive or uncontrolled angiogenesis is a major contributor to many pathological conditions whereas inhibition of aberrant angiogenesis is beneficial to patients with pathological angiogenesis. Catunaregin is a core of novel marine compound isolated from mangrove associate. The potential anti-angiogenesis of catunaregin was investigated in human umbilical vein endothelial cells (HUVECs) and zebrafish. HUVECs were treated with different concentrations of catunaregin in the presence or absence of VEGF. The angiogenic phenotypes including cell invasion cell migration and tube formation were evaluated following catunaregin treatment in HUVECs. The possible involvement of AKT, eNOS and ERK1/2 in catunaregin-induced anti-angiogenesis was explored using Western blotting. The anti-angiogenesis of catunaregin was further tested in the zebrafish embryo neovascularization and caudal fin regeneration assays. We found that catunaregin dose-dependently inhibited angiogenesis in both HUVECs and zebrafish embryo neovascularization and zebrafish caudal fin regeneration assays. In addition, catunaregin significantly decreased the phosphorylation of Akt and eNOS, but not the phosphorylation of ERK1/2. The present work demonstrates that catunaregin exerts the anti-angiogenic activity at least in part through the regulation of the Akt and eNOS signaling pathways. PMID:24824025

  7. Marine compound catunaregin inhibits angiogenesis through the modulation of phosphorylation of akt and eNOS in vivo and in vitro.

    PubMed

    Liu, Jun-Xiu; Luo, Min-Qi; Xia, Meng; Wu, Qi; Long, Si-Mei; Hu, Yaohua; Gao, Guang-Chun; Yao, Xiao-Li; He, Mian; Su, Huanxing; Luo, Xiong-Ming; Yao, Shu-Zhong

    2014-05-01

    Angiogenesis is the formation of blood vessels from pre-existing vasculature. Excessive or uncontrolled angiogenesis is a major contributor to many pathological conditions whereas inhibition of aberrant angiogenesis is beneficial to patients with pathological angiogenesis. Catunaregin is a core of novel marine compound isolated from mangrove associate. The potential anti-angiogenesis of catunaregin was investigated in human umbilical vein endothelial cells (HUVECs) and zebrafish. HUVECs were treated with different concentrations of catunaregin in the presence or absence of VEGF. The angiogenic phenotypes including cell invasion cell migration and tube formation were evaluated following catunaregin treatment in HUVECs. The possible involvement of AKT, eNOS and ERK1/2 in catunaregin-induced anti-angiogenesis was explored using Western blotting. The anti-angiogenesis of catunaregin was further tested in the zebrafish embryo neovascularization and caudal fin regeneration assays. We found that catunaregin dose-dependently inhibited angiogenesis in both HUVECs and zebrafish embryo neovascularization and zebrafish caudal fin regeneration assays. In addition, catunaregin significantly decreased the phosphorylation of Akt and eNOS, but not the phosphorylation of ERK1/2. The present work demonstrates that catunaregin exerts the anti-angiogenic activity at least in part through the regulation of the Akt and eNOS signaling pathways.

  8. Estradiol-17β modulates dose-dependently hypothalamic tyrosine hydroxylase activity inhibited by α-methylparatyrosine in the catfish Heteropneustes fossilis.

    PubMed

    Chaube, Radha; Joy, Keerikkattil P

    2011-12-01

    The brain is a target for organizational and activational effects of oestrogens synthesized de novo or transported from the peripheral organs. A neuroprotective role of oestrogens has been documented in a variety of vertebrates. In the present study in the catfish Heteropneustes fossilis, we have demonstrated that estradiol-17β (E(2)), the major circulating oestrogen at low dosages (0.05 and 0.1 μg/g body weight of fish for 3 days) stimulated hypothalamic tyrosine hydroxylase (TH) activity, and countered the negative effects of ovariectomy (3-week) or α-methylparatyrosine (α-MPT: 250 μg/g body weight, a competitive inhibitor of TH). In contrast, high dosages of E(2) (1 and 2 μg/g body weight of fish for 3 days) were inhibitory and further amplified the inhibitory effects of ovariectomy and α-MPT. The inhibiting role of E(2) was higher in gonad-active (prespawning) phase than gonad-inactive (resting phase) phase. The dual roles of E(2) may ensure a tight regulation of catecholaminergic activity, activating and inhibiting the system against wide fluctuations that are characteristic of seasonally breeding animals.

  9. Fentanyl inhibits the progression of human gastric carcinoma MGC-803 cells by modulating NF-κB-dependent gene expression in vivo

    PubMed Central

    HE, GUODONG; LI, LI; GUAN, ENJIAN; CHEN, JING; QIN, YI; XIE, YUBO

    2016-01-01

    Fentanyl is widely used to treat acute and chronic pain. Previous in vitro studies by the present authors demonstrated that fentanyl inhibits the progression of the MGC-803 human gastric carcinoma cell line by affecting apoptosis-related genes, including nuclear factor-kappa B (NF-κB) and phosphatase and tensin homolog. In the present study, the effects of fentanyl on NF-κB-dependent gene expression were investigated in vivo. Nude mice were inoculated with an MGC-803 cell suspension, and mice that developed subcutaneous tumors measuring >1.0×1.0 cm were selected for study. Mice were administered intraperitoneal injections of fentanyl (0.05 mg/kg, group F1; 0.1 mg/kg, group F2; 0.2 mg/kg, group F3; and 0.4 mg/kg, group F4) for 14 consecutive days. Non-fentanyl-treated mice (group C) and normal saline-treated mice (group N) served as the control groups. Tumor growth was monitored by calculating the time-shift of the growth curve. Morphological changes were also observed using microscopy. The expression of NF-κB, B-cell lymphoma-2 (Bcl-2), B-cell associated X protein (Bax), vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) in the subcutaneous tumor tissue was also analyzed by reverse transcription-polymerase chain reaction and western blot analysis, and confirmed using immunohistochemistry. The relative tumor volumes of groups F1, F2, F3 and F4 were significantly reduced compared with groups C and N. Furthermore, subcutaneous tumor cells exhibited nuclear swelling, chromatin condensation, reduced chromatin and nuclear fragmentation in the F1, F2, F3 and F4 groups. The number of NF-κB+, Bcl-2+, VEGF-A+ and MMP-9+ subcutaneous tumor cells was reduced, whereas the number of Bax+ cells was increased in the F1, F2, F3 and F4 groups. Additionally, in these groups, tumor expression of NF-κB, Bcl-2, VEGF-A and MMP-9 transcripts and proteins was downregulated, while Bax messenger RNA and protein expression levels were upregulated. The

  10. G1-4A, a Polysaccharide from Tinospora cordifolia Inhibits the Survival of Mycobacterium tuberculosis by Modulating Host Immune Responses in TLR4 Dependent Manner

    PubMed Central

    Gupta, Pramod Kumar; Chakraborty, Pampi; Kumar, Santosh; Singh, Prafull Kumar; Rajan, M. G. R.; Sainis, Krishna B.; Kulkarni, Savita

    2016-01-01

    Rapid emergence of drug resistance in Mycobacterium tuberculosis (MTB) is a major health concern and demands the development of novel adjunct immunotherapeutic agents capable of modulating the host immune responses in order to control the pathogen. In the present study, we sought to investigate the immunomodulatory effects of G1-4A, a polysaccharide derived from the Indian medicinal plant Tinospora cordifolia, in in-vitro and aerosol mouse models of MTB infection. G1-4A treatment of MTB infected RAW264.7 macrophages significantly induced the surface expression of MHC-II and CD-86 molecules, secretion of proinflammatory cytokines (TNF-α, IL-β, IL-6, IL-12, IFN-γ) and nitric oxide leading to reduced intracellular survival of both drug sensitive (H37Rv) as well as multi drug resistant strains (Beijing and LAM) of MTB, which was partially attributed to G1-4A induced NO production in TLR4-MyD88 dependent manner. Similarly, bacillary burden was significantly reduced in the lungs of MTB infected BALB/c mice treated with G1-4A, with simultaneous up-regulation of the expression of TNF-α, INF-γ and NOS2 in the mouse lung along with increased levels of Th1 cytokines like IFN-γ, IL-12 and decreased levels of Th2 cytokine like IL-4 in the serum. Furthermore, combination of G1-4A with Isoniazid (INH) exhibited better protection against MTB compared to that due to INH or G1-4A alone, suggesting its potential as adjunct therapy. Our results demonstrate that modulation of host immune responses by G1-4A might improve the therapeutic efficacy of existing anti-tubercular drugs and provide an attractive strategy for the development of alternative therapies to control tuberculosis. PMID:27148868

  11. G1-4A, a Polysaccharide from Tinospora cordifolia Inhibits the Survival of Mycobacterium tuberculosis by Modulating Host Immune Responses in TLR4 Dependent Manner.

    PubMed

    Gupta, Pramod Kumar; Chakraborty, Pampi; Kumar, Santosh; Singh, Prafull Kumar; Rajan, M G R; Sainis, Krishna B; Kulkarni, Savita

    2016-01-01

    Rapid emergence of drug resistance in Mycobacterium tuberculosis (MTB) is a major health concern and demands the development of novel adjunct immunotherapeutic agents capable of modulating the host immune responses in order to control the pathogen. In the present study, we sought to investigate the immunomodulatory effects of G1-4A, a polysaccharide derived from the Indian medicinal plant Tinospora cordifolia, in in-vitro and aerosol mouse models of MTB infection. G1-4A treatment of MTB infected RAW264.7 macrophages significantly induced the surface expression of MHC-II and CD-86 molecules, secretion of proinflammatory cytokines (TNF-α, IL-β, IL-6, IL-12, IFN-γ) and nitric oxide leading to reduced intracellular survival of both drug sensitive (H37Rv) as well as multi drug resistant strains (Beijing and LAM) of MTB, which was partially attributed to G1-4A induced NO production in TLR4-MyD88 dependent manner. Similarly, bacillary burden was significantly reduced in the lungs of MTB infected BALB/c mice treated with G1-4A, with simultaneous up-regulation of the expression of TNF-α, INF-γ and NOS2 in the mouse lung along with increased levels of Th1 cytokines like IFN-γ, IL-12 and decreased levels of Th2 cytokine like IL-4 in the serum. Furthermore, combination of G1-4A with Isoniazid (INH) exhibited better protection against MTB compared to that due to INH or G1-4A alone, suggesting its potential as adjunct therapy. Our results demonstrate that modulation of host immune responses by G1-4A might improve the therapeutic efficacy of existing anti-tubercular drugs and provide an attractive strategy for the development of alternative therapies to control tuberculosis. PMID:27148868

  12. G1-4A, a Polysaccharide from Tinospora cordifolia Inhibits the Survival of Mycobacterium tuberculosis by Modulating Host Immune Responses in TLR4 Dependent Manner.

    PubMed

    Gupta, Pramod Kumar; Chakraborty, Pampi; Kumar, Santosh; Singh, Prafull Kumar; Rajan, M G R; Sainis, Krishna B; Kulkarni, Savita

    2016-01-01

    Rapid emergence of drug resistance in Mycobacterium tuberculosis (MTB) is a major health concern and demands the development of novel adjunct immunotherapeutic agents capable of modulating the host immune responses in order to control the pathogen. In the present study, we sought to investigate the immunomodulatory effects of G1-4A, a polysaccharide derived from the Indian medicinal plant Tinospora cordifolia, in in-vitro and aerosol mouse models of MTB infection. G1-4A treatment of MTB infected RAW264.7 macrophages significantly induced the surface expression of MHC-II and CD-86 molecules, secretion of proinflammatory cytokines (TNF-α, IL-β, IL-6, IL-12, IFN-γ) and nitric oxide leading to reduced intracellular survival of both drug sensitive (H37Rv) as well as multi drug resistant strains (Beijing and LAM) of MTB, which was partially attributed to G1-4A induced NO production in TLR4-MyD88 dependent manner. Similarly, bacillary burden was significantly reduced in the lungs of MTB infected BALB/c mice treated with G1-4A, with simultaneous up-regulation of the expression of TNF-α, INF-γ and NOS2 in the mouse lung along with increased levels of Th1 cytokines like IFN-γ, IL-12 and decreased levels of Th2 cytokine like IL-4 in the serum. Furthermore, combination of G1-4A with Isoniazid (INH) exhibited better protection against MTB compared to that due to INH or G1-4A alone, suggesting its potential as adjunct therapy. Our results demonstrate that modulation of host immune responses by G1-4A might improve the therapeutic efficacy of existing anti-tubercular drugs and provide an attractive strategy for the development of alternative therapies to control tuberculosis.

  13. Fractionated Radiotherapy with 3 x 8 Gy Induces Systemic Anti-Tumour Responses and Abscopal Tumour Inhibition without Modulating the Humoral Anti-Tumour Response

    PubMed Central

    Habets, Thomas H. P. M.; Oth, Tammy; Houben, Ans W.; Huijskens, Mirelle J. A. J.; Senden-Gijsbers, Birgit L. M. G.; Schnijderberg, Melanie C. A.; Brans, Boudewijn; Dubois, Ludwig J.; Lambin, Philippe; De Saint-Hubert, Marijke; Germeraad, Wilfred T. V.; Tilanus, Marcel G. J.; Mottaghy, Felix M.

    2016-01-01

    Accumulating evidence indicates that fractionated radiotherapy (RT) can result in distant non-irradiated (abscopal) tumour regression. Although preclinical studies indicate the importance of T cells in this infrequent phenomenon, these studies do not preclude that other immune mechanisms exhibit an addition role in the abscopal effect. We therefore addressed the question whether in addition to T cell mediated responses also humoral anti-tumour responses are modulated after fractionated RT and whether systemic dendritic cell (DC) stimulation can enhance tumour-specific antibody production. We selected the 67NR mammary carcinoma model since this tumour showed spontaneous antibody production in all tumour-bearing mice. Fractionated RT to the primary tumour was associated with a survival benefit and a delayed growth of a non-irradiated (contralateral) secondary tumour. Notably, fractionated RT did not affect anti-tumour antibody titers and the composition of the immunoglobulin (Ig) isotypes. Likewise, we demonstrated that treatment of tumour-bearing Balb/C mice with DC stimulating growth factor Flt3-L did neither modulate the magnitude nor the composition of the humoral immune response. Finally, we evaluated the immune infiltrate and Ig isotype content of the tumour tissue using flow cytometry and found no differences between treatment groups that were indicative for local antibody production. In conclusion, we demonstrate that the 67NR mammary carcinoma in Balb/C mice is associated with a pre-existing antibody response. And, we show that in tumour-bearing Balb/C mice with abscopal tumour regression such pre-existing antibody responses are not altered upon fractionated RT and/or DC stimulation with Flt3-L. Our research indicates that evaluating the humoral immune response in the setting of abscopal tumour regression is not invariably associated with therapeutic effects. PMID:27427766

  14. The Internal Region Leucine-rich Repeat 6 of Decorin Interacts with Low Density Lipoprotein Receptor-related Protein-1, Modulates Transforming Growth Factor (TGF)-β-dependent Signaling, and Inhibits TGF-β-dependent Fibrotic Response in Skeletal Muscles*

    PubMed Central

    Cabello-Verrugio, Claudio; Santander, Cristian; Cofré, Catalina; Acuña, Maria José; Melo, Francisco; Brandan, Enrique

    2012-01-01

    Decorin is a small proteoglycan, composed of 12 leucine-rich repeats (LRRs) that modulates the activity of transforming growth factor type β (TGF-β) and other growth factors, and thereby influences proliferation and differentiation in a wide array of physiological and pathological processes, such as fibrosis, in several tissues and organs. Previously we described two novel modulators of the TGF-β-dependent signaling pathway: LDL receptor-related protein (LRP-1) and decorin. Here we have determined the regions in decorin that are responsible for interaction with LRP-1 and are involved in TGF-β-dependent binding and signaling. Specifically, we used decorin deletion mutants, as well as peptides derived from internal LRR regions, to determine the LRRs responsible for these decorin functions. Our results indicate that LRR6 and LRR5 participate in the interaction with LRP-1 and TGF-β as well as in its dependent signaling. Furthermore, the internal region (LRR6i), composed of 11 amino acids, is responsible for decorin binding to LRP-1 and subsequent TGF-β-dependent signaling. Furthermore, using an in vivo approach, we also demonstrate that the LRR6 region of decorin can inhibit TGF-β mediated action in response to skeletal muscle injury. PMID:22203668

  15. Stromal Cells Positively and Negatively Modulate the Growth of Cancer Cells: Stimulation via the PGE2-TNFα-IL-6 Pathway and Inhibition via Secreted GAPDH-E-Cadherin Interaction

    PubMed Central

    Kawada, Manabu; Inoue, Hiroyuki; Ohba, Shun-ichi; Yoshida, Junjiro; Masuda, Tohru; Yamasaki, Manabu; Usami, Ihomi; Sakamoto, Shuichi; Abe, Hikaru; Watanabe, Takumi; Yamori, Takao; Shibasaki, Masakatsu; Nomoto, Akio

    2015-01-01

    Fibroblast-like stromal cells modulate cancer cells through secreted factors and adhesion, but those factors are not fully understood. Here, we have identified critical stromal factors that modulate cancer growth positively and negatively. Using a cell co-culture system, we found that gastric stromal cells secreted IL-6 as a growth and survival factor for gastric cancer cells. Moreover, gastric cancer cells secreted PGE2 and TNFα that stimulated IL-6 secretion by the stromal cells. Furthermore, we found that stromal cells secreted glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Extracellular GAPDH, or its N-terminal domain, inhibited gastric cancer cell growth, a finding confirmed in other cell systems. GAPDH bound to E-cadherin and downregulated the mTOR-p70S6 kinase pathway. These results demonstrate that stromal cells could regulate cancer cell growth through the balance of these secreted factors. We propose that negative regulation of cancer growth using GAPDH could be a new anti-cancer strategy. PMID:25785838

  16. TOP 1 and 2, polysaccharides from Taraxacum officinale, inhibit NFκB-mediated inflammation and accelerate Nrf2-induced antioxidative potential through the modulation of PI3K-Akt signaling pathway in RAW 264.7 cells.

    PubMed

    Park, Chung Mu; Cho, Chung Won; Song, Young Sun

    2014-04-01

    Anti-inflammatory and anti-oxidative activities of polysaccharides from Taraxacum officinale (TOP 1 and 2) were analyzed in RAW 264.7 cells. First, lipopolysaccharide (LPS) was applied to identify anti-inflammatory activity of TOPs, which reduced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α. TOPs treatment inhibited phosphorylation of inflammatory transcription factor, nuclear factor (NF)κB, and its upstream signaling molecule, PI3K/Akt. Second, cytoprotective potential of TOPs against oxidative stress was investigated via heme oxygenase (HO)-1 induction. HO-1, one of phase II enzymes shows antioxidative activity, was potently induced by TOPs treatment, which was in accordance with the nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). In addition, TOPs treatment phosphorylated PI3K/Akt with slight activation of c-Jun NH2-terminal kinase (JNK). TOPs-mediated HO-1 induction protected macrophage cells from oxidative stress-induced cell death, which was confirmed by SnPP and CoPP (HO-1 inhibitor and inducer, respectively). Consequently, TOPs potently inhibited NFκB-mediated inflammation and accelerated Nrf2-mediated antioxidative potential through the modulation of PI3K/Akt pathway, which would contribute to their promising strategy for novel anti-inflammatory and anti-oxidative agents.

  17. In vitro modulation of macrophage phenotype and inhibition of polymer degradation by dexamethasone in a human macrophage/Fe/stress system.

    PubMed

    Casas, J; Zhao, Q; Donovan, M; Schroeder, P; Stokes, K; Untereker, D

    1999-09-15

    A new in vitro accelerated biological model, the macrophage-FeCl2-stress system was used for the evaluation of dexamethasone (DEX)-polymer formulations. This model combines the effects of cells (macrophages), transition metal ions (Fe2+), and polymer stress to promote material biodegradation. The cell and material effects of DEX, either in solution or incorporated into a polyetherurethane matrix (DEX/PEU), were monitored. Cell morphology and hydroperoxide formation in the polymer during cell culturing were characterized. After a subsequent treatment with FeCl2 the development of environmental stress cracking in the polymer was evaluated. We attempted to duplicate the biodegradation of PEU in terms of environmental stress cracking (ESC). Our results support the direct involvement of macrophages in polyetherurethane oxidation, probably by inducing hydroperoxide formation in the polymer structure. Under the influence of stress or strain, polymers with sufficient hydroperoxides degrade in the presence of Fe2+ metal ions in a manner that closely resembles the stress cracking that is observed in vivo. By contrast, polymers treated with either agents that inhibit cell activation and/or the oxidative burst, or with cells with no oxidative burst did not show signs of the biodegradative process. We demonstrated a reduction in hydroperoxide formation and no later ESC development in macrophage-cultured PEU in the presence of DEX in solution or in DEX-loaded PEU. We believe the prevention of initial polymer oxidation by reducing the cell's potential to produce oxidative stress at the tissue-biomaterial interface can directly inhibit the ESC degradation of chronically implanted polymers. The in vitro macrophage-Fe-stress system is a valuable tool for reliable assessment and cost-effective evaluation of biomaterials. PMID:10398008

  18. A selective estrogen receptor modulator inhibits TNF-alpha-induced apoptosis by activating ERK1/2 signaling pathway in vascular endothelial cells.

    PubMed

    Yu, Jing; Eto, Masato; Akishita, Masahiro; Okabe, Tetsuro; Ouchi, Yasuyoshi

    2009-07-01

    Tumor necrosis factor (TNF-alpha) is a pleiotropic cytokine exerting both inflammatory and cell death activity and is thought to play a role in the pathogenesis of atherosclerosis. The present study was designed to examine whether the raloxifene analogue, LY117018 could inhibit TNF-alpha-induced apoptosis in vascular endothelial cells and to clarify the involved mechanisms. Apoptosis of endothelial cells was determined by DNA fragmentation assay and the activation of caspase-3. LY117018 significantly inhibited TNF-alpha-induced caspase-3 activation and cell DNA fragmentation levels in bovine carotid artery endothelial cells. The inhibitory effect of LY117018 was abolished by an estrogen receptor antagonist ICI 182,780. p38 MAPK, JNK, ERK1/2 and Akt have been shown to act as apoptotic or anti-apoptotic signals. TNF-alpha stimulated the phosphorylation levels of p38 MAPK, JNK, ERK1/2 and Akt in vascular endothelial cells. TNF-alpha-induced apoptosis was significantly decreased by SB203580, a p38 MAPK inhibitor or SP600125, a JNK inhibitor, but was enhanced by an ERK1/2 pathway inhibitor, PD98059 or a PI3-kinase/Akt pathway inhibitor, wortmannin. The anti-apoptotic effect of LY117018 was abrogated only by PD98059 but was not affected by the inhibitors for p38 MAPK, JNK, or Akt. LY117018 stimulated the further increase in phosphorylation of ERK1/2 in TNF-alpha treated endothelial cells but it did not affect phosphorylation levels of p38 MAPK, JNK or Akt. These results suggest that LY 110718 prevents caspase-3 dependent apoptosis induced by TNF-alpha in vascular endothelial cells through activation of the estrogen receptors and the ERK1/2 signaling pathway. PMID:19275968

  19. Sphingosine-1-phosphate inhibits PDGF-induced chemotaxis of human arterial smooth muscle cells: spatial and temporal modulation of PDGF chemotactic signal transduction

    PubMed Central

    1995-01-01

    Activation of the PDGF receptor on human arterial smooth muscle cells (SMC) induces migration and proliferation via separable signal transduction pathways. Sphingosine-1-phosphate (Sph-1-P) can be formed following PDGF receptor activation and therefore may be implicated in PDGF-receptor signal transduction. Here we show that Sph-1-P does not significantly affect PDGF-induced DNA synthesis, proliferation, or activation of mitogenic signal transduction pathways, such as the mitogen-activated protein (MAP) kinase cascade and PI 3-kinase, in human arterial SMC. On the other hand, Sph-1-P strongly mimics PDGF receptor-induced chemotactic signal transduction favoring actin filament disassembly. Although Sph-1-P mimics PDGF, exogenously added Sph-1-P induces more prolonged and quantitatively greater PIP2 hydrolysis compared to PDGF-BB, a markedly stronger calcium mobilization and a subsequent increase in cyclic AMP levels and activation of cAMP-dependent protein kinase. This excessive and prolonged signaling favors actin filament disassembly by Sph-1-P, and results in inhibition of actin nucleation, actin filament assembly and formation of focal adhesion sites. Sph-1-P-induced interference with the dynamics of PDGF-stimulated actin filament disassembly and assembly results in a marked inhibition of cell spreading, of extension of the leading lamellae toward PDGF, and of chemotaxis toward PDGF. The results suggest that spatial and temporal changes in phosphatidylinositol turnover, calcium mobilization and actin filament disassembly may be critical to PDGF-induced chemotaxis and suggest a possible role for endogenous Sph-1-P in the regulation of PDGF receptor chemotactic signal transduction. PMID:7790372

  20. Lactobacillus amylovorus Inhibits the TLR4 Inflammatory Signaling Triggered by Enterotoxigenic Escherichia coli via Modulation of the Negative Regulators and Involvement of TLR2 in Intestinal Caco-2 Cells and Pig Explants

    PubMed Central

    Finamore, Alberto; Roselli, Marianna; Imbinto, Ambra; Seeboth, Julie; Oswald, Isabelle P.; Mengheri, Elena

    2014-01-01

    Inflammation derived from pathogen infection involves the activation of toll-like receptor (TLR) signaling. Despite the established immunomodulatory activities of probiotics, studies relating the ability of such bacteria to inhibit the TLR signaling pathways are limited or controversial. In a previous study we showed that Lactobacillus amylovorus DSM 16698T, a novel lactobacillus isolated from unweaned pigs, protects the intestinal cells from enterotoxigenic Escherichia coli (ETEC) K88 infection through cytokine regulation. In the present study we investigated whether the ability of L. amylovorus to counteract the inflammatory status triggered by ETEC in intestine is elicited through inhibition of the TLR4 signaling pathway. We used the human intestinal Caco-2/TC7 cells and intestinal explants isolated from 5 week-old crossbreed Pietrain/Duroc/Large-White piglets, treated with ETEC, L. amylovorus or L. amylovorus cell free supernatant, either alone or simultaneously with ETEC. Western blot analysis showed that L. amylovorus and its cell free supernatant suppress the activation of the different steps of TLR4 signaling in Caco-2/TC7 cells and pig explants, by inhibiting the ETEC induced increase in the level of TLR4 and MyD88, the phosphorylation of the IKKα, IKKβ, IκBα and NF-κB subunit p65, as well as the over-production of inflammatory cytokines IL-8 and IL-1β. The immunofluorescence analysis confirms the lack of phospho-p65 translocation into the nucleus. These anti-inflammatory effects are achieved through modulation of the negative regulators Tollip and IRAK-M. We also found that L. amylovorus blocks the up-regulation of the extracellular heat shock protein (Hsp)72 and Hsp90, that are critical for TLR4 function. By using anti-TLR2 antibody, we demonstrate that TLR2 is required for the suppression of TLR4 signaling activation. These results may contribute to develop therapeutic interventions using L. amylovorus in intestinal disorders of piglets and humans

  1. Astragalus and Paeoniae radix rubra extract inhibits liver fibrosis by modulating the transforming growth factor‑β/Smad pathway in rats.

    PubMed

    Huang, Weijuan; Li, Lin; Tian, Xiaopeng; Yan, Jinjin; Yang, Xinzheng; Wang, Xinlong; Liao, Guozhen; Qiu, Genquan

    2015-02-01

    It has been previously demonstrated that Astragalus and Paeoniae radix rubra extract (APE) had a protective effect against liver fibrosis in mice. The present study aimed to investigate the hepatoprotective effect of APE on CCl4‑induced hepatic fibrosis in rats. Liver fibrosis was induced in male Sprague‑Dawley rats by intraperitoneal injection of 50% CCl4 twice a week for eight weeks. Organ coefficients, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), hexadecenoic acid (HA), laminin (LN), procollagen type III (PCIII), hydroxyproline (Hyp), glutathione (GSH‑Px), malondialdehyde (MDA), superoxide dismutase (SOD) and transforming growth factor β1 (TGF‑β1) levels were measured in rats with hepatic fibrosis. Histopathological changes in affected livers were studied using hematoxylin‑eosin and Masson's trichrome staining. The expression of transforming growth factor‑β/Smad pathway proteins, α‑smooth muscle actin (α‑SMA), collagen I and collagen III was observed in fibrotic livers using western blot analysis. The present study observed significant reductions in serum levels of AST, ALT, HA, LN, PCIII and Hyp in APE‑treated (2.6 and 5.2 g/kg) rats, indicating the significant hepatoprotective effects of APE. Furthermore, the depletion of GSH‑Px and SOD, in addition to the accumulation of MDA in liver tissue was suppressed by APE (2.6 and 5.2 g/kg). Pathological assessment of CCl4‑induced fibrotic livers revealed a significant reduction of liver injury and development of hepatic fibrosis in rats treated with APE (2.6 and 5.2 g/kg). Moreover, APE (2.6 and 5.2 g/kg) decreased the elevation of TGF‑β1, α‑SMA, collagen I and collagen III expression, inhibited Smad2/3 phosphorylation as well as elevated the expression of the TGF‑β1 inhibitor Smad7. These results suggested that APE may protect against liver damage and inhibit the progression of CCl4‑induced hepatic fibrosis. The mechanism of action of APE is

  2. Genistein inhibition of OGD-induced brain neuron death correlates with its modulation of apoptosis, voltage-gated potassium and sodium currents and glutamate signal pathway.

    PubMed

    Ma, Xue-Ling; Zhang, Feng; Wang, Yu-Xiang; He, Cong-Cong; Tian, Kun; Wang, Hong-Gang; An, Di; Heng, Bin; Liu, Yan-Qiang

    2016-07-25

    In the present study, we established an in vitro model of hypoxic-ischemia via exposing primary neurons of newborn rats to oxygen-glucose deprivation (OGD) and observing the effects of genistein, a soybean isoflavone, on hypoxic-ischemic neuron viability, apoptosis, voltage-activated potassium (Kv) and sodium (Nav) currents, and glutamate receptor subunits. The results indicated that OGD exposure reduced the viability and increased the apoptosis of brain neurons. Meanwhile, OGD exposure caused changes in the current-voltage curves and current amplitude values of voltage-activated potassium and sodium currents; OGD exposure also decreased GluR2 expression and increased NR2 expression. However, genistein at least partially reversed the effects caused by OGD. The results suggest that hypoxic-ischemia-caused neuronal apoptosis/death is related to an increase in K(+) efflux, a decrease in Na(+) influx, a down-regulation of GluR2, and an up-regulation of NR2. Genistein may exert some neuroprotective effects via the modulation of Kv and Nav currents and the glutamate signal pathway, mediated by GluR2 and NR2. PMID:27238724

  3. BAM 1 and RECEPTOR-LIKE PROTEIN KINASE 2 constitute a signaling pathway and modulate CLE peptide-triggered growth inhibition in Arabidopsis root.

    PubMed

    Shimizu, Noriko; Ishida, Takashi; Yamada, Masashi; Shigenobu, Shuji; Tabata, Ryo; Kinoshita, Atsuko; Yamaguchi, Katsushi; Hasebe, Mitsuyasu; Mitsumasu, Kanako; Sawa, Shinichiro

    2015-12-01

    Ligand receptor-based signaling is a means of cell-to-cell communication for coordinating developmental and physiological processes in multicellular organisms. In plants, cell-producing meristems utilize this signaling to regulate their activities and ensure for proper development. Shoot and root systems share common requirements for carrying out this process; however, its molecular basis is largely unclear. It has been suggested that synthetic CLV3/EMBRYO SURROUNDING REGION (CLE) peptide shrinks the root meristem through the actions of CLAVATA2 (CLV2) and the RECEPTOR-LIKE PROTEIN KINASE 2 (RPK2) pathway in Arabidopsis thaliana. Our genetic screening for mutations that resist CLE peptide signaling in roots determined that BAM1, which is a member of the leucine-rich repeat receptor-like kinase (LRR-RLK) family, is also involved in this pathway. BAM1 is preferentially expressed in the root tip, including the quiescent center and its surrounding stem cells. Our genetic analysis revealed that BAM1 functions together with RPK2. Using coimmunoprecipitation assay, we showed that BAM1 is capable of forming heteromeric complexes with RPK2. These findings suggest that the BAM1 and RPK2 receptors constitute a signaling pathway that modulates cell proliferation in the root meristem and that related molecules are employed in root and shoot meristems. PMID:26083273

  4. Using structural-based protein engineering to modulate the differential inhibition effects of SAUGI on human and HSV uracil DNA glycosylase.

    PubMed

    Wang, Hao-Ching; Ho, Chun-Han; Chou, Chia-Cheng; Ko, Tzu-Ping; Huang, Ming-Fen; Hsu, Kai-Cheng; Wang, Andrew H-J

    2016-05-19

    Uracil-DNA glycosylases (UDGs) are highly conserved proteins that can be found in a wide range of organisms, and are involved in the DNA repair and host defense systems. UDG activity is controlled by various cellular factors, including the uracil-DNA glycosylase inhibitors, which are DNA mimic proteins that prevent the DNA binding sites of UDGs from interacting with their DNA substrate. To date, only three uracil-DNA glycosylase inhibitors, phage UGI, p56, and Staphylococcus aureus SAUGI, have been determined. We show here that SAUGI has differential inhibitory effects on UDGs from human, bacteria, Herpes simplex virus (HSV; human herpesvirus 1) and Epstein-Barr virus (EBV; human herpesvirus 4). Newly determined crystal structures of SAUGI/human UDG and a SAUGI/HSVUDG complex were used to explain the differential binding activities of SAUGI on these two UDGs. Structural-based protein engineering was further used to modulate the inhibitory ability of SAUGI on human UDG and HSVUDG. The results of this work extend our understanding of DNA mimics as well as potentially opening the way for novel therapeutic applications for this kind of protein.

  5. Anti IL-17A therapy inhibits bone loss in TNF-α-mediated murine arthritis by modulation of the T-cell balance.

    PubMed

    Zwerina, Karin; Koenders, Marije; Hueber, Axel; Marijnissen, Renoud J; Baum, Wolfgang; Heiland, Gisela Ruiz; Zaiss, Mario; McLnnes, Iain; Joosten, Leo; van den Berg, Wim; Zwerina, Jochen; Schett, Georg

    2012-02-01

    Tumour necrosis factor alpha (TNF-α) is a major inducer for inflammation and bone loss. Here, we investigated whether interleukin (IL)-17 plays a role in TNF-α-mediated inflammation and bone resorption. Human TNF-α transgenic (hTNFtg) mice were treated with a neutralizing anti-IL-17A antibody and assessed for inflammation, cartilage and bone damage. T-cell transcription factors and lymphokine patterns were measured in the LNs. IL-17A inhibition in the absence of IL-1 was also evaluated by treating hTNFtg/IL-1(-/-) mice with an IL-17A neutralizing antibody. IL-17A neutralization had only minor effects on TNF-α-induced inflammation but effectively reduced local and systemic bone loss by blocking osteoclast differentiation in vivo. Effects were based on a shift to bone-protective T-cell responses such as enhanced Th2 differentiation, IL-4 and IL-12 expression and Treg cell numbers. Whereas inflammation in hTNFtg/IL-1(-/-) mice was highly sensitive to IL-17A blockade, no shift in the T-cell lineages and no additional benefit on bone mass were observed in response to IL-17A neutralization. We thus conclude that IL-17A is a key mediator of TNF-α-induced bone loss by closely interacting with IL-1 in blocking bone protective T-cell responses.

  6. Long Non-coding RNA H19 Inhibits Adipocyte Differentiation of Bone Marrow Mesenchymal Stem Cells through Epigenetic Modulation of Histone Deacetylases

    PubMed Central

    Huang, Yiping; Zheng, Yunfei; Jin, Chanyuan; Li, Xiaobei; Jia, Lingfei; Li, Weiran

    2016-01-01

    Bone marrow mesenchymal stem cells (BMSCs) exhibit an increased propensity toward adipocyte differentiation accompanied by a reduction in osteogenesis in osteoporotic bone marrow. However, limited knowledge is available concerning the role of long non-coding RNAs (lncRNAs) in the differentiation of BMSCs into adipocytes. In this study, we demonstrated that lncRNA H19 and microRNA-675 (miR-675) derived from H19 were significantly downregulated in BMSCs that were differentiating into adipocytes. Overexpression of H19 and miR-675 inhibited adipogenesis, while knockdown of their endogenous expression accelerated adipogenic differentiation. Mechanistically, we found that miR-675 targeted the 3′ untranslated regions of the histone deacetylase (HDAC) 4–6 transcripts and resulted in deregulation of HDACs 4–6, essential molecules in adipogenesis. In turn, trichostatin A, an HDAC inhibitor, significantly reduced CCCTC-binding factor (CTCF) occupancy in the imprinting control region upstream of the H19 gene locus and subsequently downregulated the expression of H19. These results show that the CTCF/H19/miR-675/HDAC regulatory pathway plays an important role in the commitment of BMSCs into adipocytes. PMID:27349231

  7. Atrial natriuretic peptide (ANP) inhibits DMBA/croton oil induced skin tumor growth by modulating NF-κB, MMPs, and infiltrating mast cells in swiss albino mice.

    PubMed

    Subramanian, Vimala; Vellaichamy, Elangovan

    2014-10-01

    Cardiac hormone atrial natriuretic peptide (ANP) and its receptor, natriuretic peptide receptor-A (NPR-A) are implicated as a vital regulator of cancer cell growth and tumor progression. However, the underlying mechanism by which ANP opposes the cancer growth in in-vivo remains unknown. Herein, we investigated the anti-cancer activity of ANP on 7, 12-dimethyl benzanthracence (DMBA)/Croton oil- induced two-step skin carcinogenic mouse model. Skin tumor incidence and tumor volume were recorded during the experimental period of 16 weeks. ANP (1 μg/kg body weight/alternate days for 4 weeks) was injected subcutaneously from the 13th week of DMBA/Croton oil induction. ANP treatment markedly inhibited the skin tumor growth (P<0.001). A significant reduction in the level of NF-κB activation (P<0.001), infiltrating mast cell count (P<0.01) and MMP-2/-9 (P<0.001, respectively) were noticed in the ANP treated mice skin tissue. Further, ANP treatment revert back the altered levels of serum LDH-4, C-reactive protein (CRP), and enzymatic antioxidants (SOD and CAT activities) to near normal level. Taken together, the results of this study suggest that ANP opposes the skin carcinogenesis by suppressing the inflammatory response and MMPs.

  8. Bidens pilosa and its active compound inhibit adipogenesis and lipid accumulation via down-modulation of the C/EBP and PPARγ pathways

    PubMed Central

    Liang, Yu-Chuan; Yang, Meng-Ting; Lin, Chuan-Ju; Chang, Cicero Lee-Tian; Yang, Wen-Chin

    2016-01-01

    Obesity and its complications are a major global health problem. In this study, we investigated the anti-obesity effect and mechanism of an edible plant, Bidens pilosa, and its active constituent. We first assessed the long-term effect of B. pilosa on body composition, body weight, blood parameters in ICR mice. We observed that it significantly decreased fat content and increased protein content in ICR mice. Next, we verified the anti-obesity effect of B. pilosa in ob/ob mice. It effectively and dose-dependently reduced fat content, adipocyte size and/or body weight in mice. Moreover, mechanistic studies showed that B. pilosa inhibited the expression of peroxisome proliferator activated receptor γ (PPARγ), CCAAT/enhancer binding proteins (C/EBPs) and Egr2 in adipose tissue. Finally, we examined the effect of 2-β-D-glucopyranosyloxy-1-hydroxytrideca-5,7,9,11-tetrayne (GHT) on adipogenesis in adipocytes. We found that B. pilosa significantly decreased the adipogenesis and lipid accumulation. This decrease was associated with the down-regulation of expression of Egr2, C/EBPs, PPARγ, adipocyte Protein 2 (aP2) and adiponectin. In summary, this work demonstrated that B. pilosa and GHT suppressed adipogenesis and lipid content in adipocytes and/or animals via the down-regulation of the Egr2, C/EBPs and PPARγ pathways, suggesting a novel application of B. pilosa and GHT against obesity. PMID:27063434

  9. Meloxicam inhibits fipronil-induced apoptosis via modulation of the oxidative stress and inflammatory response in SH-SY5Y cells.

    PubMed

    Park, Jae Hyeon; Park, Youn Sun; Lee, Je-Bong; Park, Kyung-Hun; Paik, Min-kyoung; Jeong, Mihye; Koh, Hyun Chul

    2016-01-01

    Oxidative stress and inflammatory responses have been identified as key elements of neuronal cell apoptosis. In this study, we investigated the mechanisms by which inflammatory responses contribute to apoptosis in human neuroblastoma SH-SY5Y cells treated with fipronil (FPN). Based on the cytotoxic mechanism of FPN, we examined the neuroprotective effects of meloxicam against FPN-induced neuronal cell death. Treatment of SH-SY5Y cells with FPN induced apoptosis via activation of caspase-9 and -3, leading to nuclear condensation. In addition, FPN induced oxidative stress and increased expression of cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) via inflammatory stimulation. Pretreatment of cells with meloxicam enhanced the viability of FPN-exposed cells through attenuation of oxidative stress and inflammatory response. FPN activated mitogen activated protein kinase (MAPK) and inhibitors of MAPK abolished FPN-induced COX-2 expression. Meloxicam also attenuated FPN-induced cell death by reducing MAPK-mediated pro-inflammatory factors. Furthermore, we observed both nuclear accumulation of p53 and enhanced levels of cytosolic p53 in a concentration-dependent manner after FPN treatment. Pretreatment of cells with meloxicam blocked the translocation of p53 from the cytosol to the nucleus. Together, these data suggest that meloxicam may exert anti-apoptotic effects against FPN-induced cytotoxicity by both attenuating oxidative stress and inhibiting the inflammatory cascade via inactivation of MAPK and p53 signaling.

  10. Black Tea Extract and Its Theaflavin Derivatives Inhibit the Growth of Periodontopathogens and Modulate Interleukin-8 and β-Defensin Secretion in Oral Epithelial Cells

    PubMed Central

    Lombardo Bedran, Telma Blanca; Morin, Marie-Pierre; Palomari Spolidorio, Denise; Grenier, Daniel

    2015-01-01

    Over the years, several studies have brought evidence suggesting that tea polyphenols, mostly from green tea, may have oral health benefits. Since few data are available concerning the beneficial properties of black tea and its theaflavin derivatives against periodontal disease, the objective of this study was to investigate their antibacterial activity as well as their ability to modulate interleukin-8 and human β-defensin (hBD) secretion in oral epithelial cells. Among the periodontopathogenic bacteria tested, Porphyromonas gingivalis was found to be highly susceptible to the black tea extract and theaflavins. Moreover, our data indicated that the black tea extract, theaflavin and theaflavin-3,3’-digallate can potentiate the antibacterial effect of metronidazole and tetracycline against P. gingivalis. Using lipopolysaccharide-stimulated oral epithelial cells, the black tea extract (100 μg/ml), as well as theaflavin and theaflavin-3,3’-digallate (50 μg/ml) reduced interleukin-8 (IL-8) secretion by 85%, 79%, and 86%, respectively, thus suggesting an anti-inflammatory property. The ability of the black tea extract and its theaflavin derivatives to induce the secretion of the antimicrobial peptides hBD-1, hBD-2 and hBD-4 by oral epithelial cells was then evaluated. Our results showed that the black tea extract as well as theaflavin-3,3’-digallate were able to increase the secretion of the three hBDs. In conclusion, the ability of a black tea extract and theaflavins to exert antibacterial activity against major periodontopathogens, to attenuate the secretion of IL-8, and to induce hBD secretion in oral epithelial cells suggest that these components may have a beneficial effect against periodontal disease. PMID:26581041

  11. Black Tea Extract and Its Theaflavin Derivatives Inhibit the Growth of Periodontopathogens and Modulate Interleukin-8 and β-Defensin Secretion in Oral Epithelial Cells.

    PubMed

    Lombardo Bedran, Telma Blanca; Morin, Marie-Pierre; Palomari Spolidorio, Denise; Grenier, Daniel

    2015-01-01

    Over the years, several studies have brought evidence suggesting that tea polyphenols, mostly from green tea, may have oral health benefits. Since few data are available concerning the beneficial properties of black tea and its theaflavin derivatives against periodontal disease, the objective of this study was to investigate their antibacterial activity as well as their ability to modulate interleukin-8 and human β-defensin (hBD) secretion in oral epithelial cells. Among the periodontopathogenic bacteria tested, Porphyromonas gingivalis was found to be highly susceptible to the black tea extract and theaflavins. Moreover, our data indicated that the black tea extract, theaflavin and theaflavin-3,3'-digallate can potentiate the antibacterial effect of metronidazole and tetracycline against P. gingivalis. Using lipopolysaccharide-stimulated oral epithelial cells, the black tea extract (100 μg/ml), as well as theaflavin and theaflavin-3,3'-digallate (50 μg/ml) reduced interleukin-8 (IL-8) secretion by 85%, 79%, and 86%, respectively, thus suggesting an anti-inflammatory property. The ability of the black tea extract and its theaflavin derivatives to induce the secretion of the antimicrobial peptides hBD-1, hBD-2 and hBD-4 by oral epithelial cells was then evaluated. Our results showed that the black tea extract as well as theaflavin-3,3'-digallate were able to increase the secretion of the three hBDs. In conclusion, the ability of a black tea extract and theaflavins to exert antibacterial activity against major periodontopathogens, to attenuate the secretion of IL-8, and to induce hBD secretion in oral epithelial cells suggest that these components may have a beneficial effect against periodontal disease. PMID:26581041

  12. Long-lasting modulation of human motor cortex following prolonged transcutaneous electrical nerve stimulation (TENS) of forearm muscles: evidence of reciprocal inhibition and facilitation.

    PubMed

    Tinazzi, Michele; Zarattini, Stefano; Valeriani, Massimiliano; Romito, Silvia; Farina, Simona; Moretto, Giuseppe; Smania, Nicola; Fiaschi, Antonio; Abbruzzese, Giovanni

    2005-03-01

    Several lines of evidence indicate that motor cortex excitability can be modulated by manipulation of afferent inputs, like peripheral electrical stimulation. Most studies in humans mainly dealt with the effects of prolonged low-frequency peripheral nerve stimulation on motor cortical excitability, despite its being known from animal studies that high-frequency stimulation can also result in changes of the cortical excitability. To investigate the possible effects of high-frequency peripheral stimulation on motor cortical excitability we recorded motor-evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) of the left motor cortex from the right flexor carpi radialis (FCR), extensor carpi radialis (ECR), and first dorsal interosseous (FDI) in normal subjects, before and after transcutaneous electrical nerve stimulation (TENS) of 30 min duration applied over the FCR. The amplitude of MEPs from the FRC was significantly reduced from 10 to 35 min after TENS while the amplitude of MEPs from ECR was increased. No effects were observed in the FDI muscle. Indices of peripheral nerve (M-wave) and spinal cord excitability (H waves) did not change throughout the experiment. Electrical stimulation of the lateral antebrachial cutaneous nerve has no significant effect on motor cortex excitability. These findings suggest that TENS of forearm muscles can induce transient reciprocal inhibitory and facilitatory changes in corticomotoneuronal excitability of forearm flexor and extensor muscles lasting several minutes. These changes probably may occur at cortical site and seem to be mainly dependent on stimulation of muscle afferents. These findings might eventually lead to practical applications in rehabilitation, especially in those syndromes in which the excitatory and inhibitory balance between agonist and antagonist is severely impaired, such as spasticity and dystonia.

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

    PubMed Central

    Oliveira, Victoria Regina da Silva; Toniolo, Elaine Flamia; Feliciano, Regiane dos Santos; da Silva Jr., José Antonio; Zamuner, Stella Regina

    2016-01-01

    Background Envenoming induced by Bothrops snakebites is characterized by drastic local tissue damage that involves an intense inflammatory reaction and local hyperalgesia which are not neutralized by conventional antivenom treatment. Herein, the effectiveness of photobiomodulation to reduce inflammatory hyperalgesia induced by Bothrops moojeni venom (Bmv), as well as the mechanisms involved was investigated. Methodology/Principal Findings Bmv (1 μg) was injected through the intraplantar route in the right hind paw of mice. Mechanical hyperalgesia and allodynia were evaluated by von Frey filaments at different time points after venom injection. Low level laser therapy (LLLT) was applied at the site of Bmv injection at wavelength of red 685 nm with energy density of 2.2 J/cm2 at 30 min and 3 h after venom inoculation. Neuronal activation in the dorsal horn spinal cord was determined by immunohistochemistry of Fos protein and the mRNA expression of IL-6, TNF-α, IL-10, B1 and B2 kinin receptors were evaluated by Real time-PCR 6 h after venom injection. Photobiomodulation reversed Bmv-induced mechanical hyperalgesia and allodynia and decreased Fos expression, induced by Bmv as well as the mRNA levels of IL-6, TNF-α and B1 and B2 kinin receptors. Finally, an increase on IL-10, was observed following LLLT. Conclusion/Significance These data demonstrate that LLLT interferes with mechanisms involved in nociception and hyperalgesia and modulates Bmv-induced nociceptive signal. The use of photobiomodulation in reducing local pain induced by Bothropic venoms should be considered as a novel therapeutic tool for the treatment of local symptoms induced after bothropic snakebites. PMID:27749899

  14. Black Tea Extract and Its Theaflavin Derivatives Inhibit the Growth of Periodontopathogens and Modulate Interleukin-8 and β-Defensin Secretion in Oral Epithelial Cells.

    PubMed

    Lombardo Bedran, Telma Blanca; Morin, Marie-Pierre; Palomari Spolidorio, Denise; Grenier, Daniel

    2015-01-01

    Over the years, several studies have brought evidence suggesting that tea polyphenols, mostly from green tea, may have oral health benefits. Since few data are available concerning the beneficial properties of black tea and its theaflavin derivatives against periodontal disease, the objective of this study was to investigate their antibacterial activity as well as their ability to modulate interleukin-8 and human β-defensin (hBD) secretion in oral epithelial cells. Among the periodontopathogenic bacteria tested, Porphyromonas gingivalis was found to be highly susceptible to the black tea extract and theaflavins. Moreover, our data indicated that the black tea extract, theaflavin and theaflavin-3,3'-digallate can potentiate the antibacterial effect of metronidazole and tetracycline against P. gingivalis. Using lipopolysaccharide-stimulated oral epithelial cells, the black tea extract (100 μg/ml), as well as theaflavin and theaflavin-3,3'-digallate (50 μg/ml) reduced interleukin-8 (IL-8) secretion by 85%, 79%, and 86%, respectively, thus suggesting an anti-inflammatory property. The ability of the black tea extract and its theaflavin derivatives to induce the secretion of the antimicrobial peptides hBD-1, hBD-2 and hBD-4 by oral epithelial cells was then evaluated. Our results showed that the black tea extract as well as theaflavin-3,3'-digallate were able to increase the secretion of the three hBDs. In conclusion, the ability of a black tea extract and theaflavins to exert antibacterial activity against major periodontopathogens, to attenuate the secretion of IL-8, and to induce hBD secretion in oral epithelial cells suggest that these components may have a beneficial effect against periodontal disease.

  15. Low-frequency stimulation inhibits epileptogenesis by modulating the early network of the limbic system as evaluated in amygdala kindling model.

    PubMed

    Wang, Yi; Xu, Zhenghao; Cheng, Hui; Guo, Yi; Xu, Cenglin; Wang, Shuang; Zhang, Jianmin; Ding, Meiping; Chen, Zhong

    2014-09-01

    Low-frequency stimulation (LFS) is emerging as a new option for the treatment of epilepsy. The present study was designed to determine whether there is a crucial period for the treatment of epileptogenesis with LFS. LFS was delivered at different time-points to evaluate its anti-epileptogenic effect on amygdala-kindling rats. (18)F-fluorodeoxyglucose small-animal positron-emission tomography (microPET) and multi-channel EEG recording (MER) were used to investigate the dynamics of brain networks during epileptogenesis and LFS treatment. Interestingly, LFS delivered in the first 7 days significantly retarded the progression of behavioral seizure stages and shortened the afterdischarge duration (ADD), LFS delivered throughout the whole process resulted in similar effects. However, if LFS was delivered at the beginning of seizure stage 2 or 3 (5 ± 0.3 days during kindling acquisition), it had no anti-epileptogenic effect and even prolonged the ADD and enhanced synchronization of the EEGs. MicroPET study revealed a notable hypometabolism in the amygdala, piriform cortex, entorhinal cortex and other regions in the limbic system during the period from seizure stage 0 to stage 2 or 3. The glucose metabolism in those regions was specifically increased by LFS. MER further verified that an early network of afterdischarge spread was formed in those brain regions during kindling acquisition. Thus, we provided direct evidence that modulation of the early network in the limbic system is crucial for the anti-epileptogenic effect of LFS in amygdaloid-kindling rats.

  16. In vitro and in vivo anti-tumor activity of CoQ0 against melanoma cells: inhibition of metastasis and induction of cell-cycle arrest and apoptosis through modulation of Wnt/β-catenin signaling pathways

    PubMed Central

    Hseu, You-Cheng; Thiyagarajan, Varadharajan; Tsou, Hsiao-Tung; Lin, Kai-Yuan; Chen, Hui-Jye; Lin, Chung-Ming; Liao, Jiuun-Wang; Yang, Hsin-Ling

    2016-01-01

    Coenzyme Q0 (CoQ0, 2,3-dimethoxy-5-methyl-1,4-benzoquinone), a novel quinone derivative, has been shown to modulate cellular redox balance. However, effect of this compound on melanoma remains unclear. This study examined the in vitro or in vivo anti-tumor, apoptosis, and anti-metastasis activities of CoQ0 (0-20 μM) through inhibition of Wnt/β-catenin signaling pathway. CoQ0 exhibits a significant cytotoxic effect on melanoma cell lines (B16F10, B16F1, and A2058), while causing little toxicity toward normal (HaCaT) cells. The suppression of β-catenin was seen with CoQ0 administration accompanied by a decrease in the expression of Wnt/β-catenin transcriptional target c-myc, cyclin D1, and survivin through GSK3β-independent pathway. We found that CoQ0 treatment caused G1 cell-cycle arrest by reducing the levels of cyclin E and CDK4. Furthermore, CoQ0 treatment induced apoptosis through caspase-9/-3 activation, PARP degradation, Bcl-2/Bax dysregulation, and p53 expression. Notably, non- or sub-cytotoxic concentrations of CoQ0 markedly inhibited migration and invasion, accompanied by the down-regulation of MMP-2 and -9, and up-regulation of TIMP-1 and -2 expressions in highly metastatic B16F10 cells. Furthermore, the in vivo study results revealed that CoQ0 treatment inhibited the tumor growth in B16F10 xenografted nude mice. Histological analysis and western blotting confirmed that CoQ0 significantly decreased the xenografted tumor progression as demonstrated by induction of apoptosis, suppression of β-catenin, and inhibition of cell cycle-, apoptotic-, and metastatic-regulatory proteins. The data suggest that CoQ0 unveils a novel mechanism by down-regulating Wnt/β-catenin pathways and could be used as a potential lead compound for melanoma chemotherapy. PMID:26968952

  17. Apoptosis induced by paclitaxel via Bcl-2, Bax and caspases 3 and 9 activation in NB4 human leukaemia cells is not modulated by ERK inhibition.

    PubMed

    Morales-Cano, Daniel; Calviño, Eva; Rubio, Virginia; Herráez, Angel; Sancho, Pilar; Tejedor, M Cristina; Diez, José C

    2013-11-01

    We have studied the role of pivotal bio-molecules involved in signalling of cytotoxic effects induced by paclitaxel (Ptx) on acute promyelocytic human leukaemia NB4 cells. A time-dependent increase in cell death and DNA cleavage was observed after 30μM Ptx treatment. Cell death induction by Ptx proceeds mainly as programmed cell death as shown by annexin V-FITC, reaching up to 30% of apoptotic cells after 24h. Significant reductions of p53, changes in Bax and Bcl-2 and activation of caspases 3 and 9 were observed as the treatment was applied for long times. Ptx treatments produced NFkB depletion with expression levels abolished at 19h what could be involved in reduction of survival signals. Phosphorylation of intracellular kinases showed that pERK1/2 decreased significantly at 19h of Ptx treatment. When these cells were preincubated for 90min with 20μM PD98059, 2'-amino-3'-methoxyflavone, an inhibitor of ERK phosphorylation, a slight reduction of cell viability was observed in comparison to that produced by Ptx alone. Pretreatment with PD98059 neither activated caspases nor significantly increased the apoptotic effect of Ptx. Taken together, our data reveal that the inhibition of ERK phosphorylation does not seem to be an essential pathway for bursting an increased induction of apoptosis by Ptx. Decrease of p53 and Bcl-2, fragmentation of DNA, increase of Bax and, finally, activation of caspases 3 and 9 in NB4 leukaemia cells make the apoptotic process induced by Ptx irreversible. Application of Ptx in leukaemia cells shows therefore a promising potential with particular effects on different leukaemia cell types.

  18. Inhibition of K+ Transport through Na+, K+-ATPase by Capsazepine: Role of Membrane Span 10 of the α-Subunit in the Modulation of Ion Gating

    PubMed Central

    Mahmmoud, Yasser A.; Shattock, Michael; Cornelius, Flemming; Pavlovic, Davor

    2014-01-01

    Capsazepine (CPZ) inhibits Na+,K+-ATPase-mediated K+-dependent ATP hydrolysis with no effect on Na+-ATPase activity. In this study we have investigated the functional effects of CPZ on Na+,K+-ATPase in intact cells. We have also used well established biochemical and biophysical techniques to understand how CPZ modifies the catalytic subunit of Na+,K+-ATPase. In isolated rat cardiomyocytes, CPZ abolished Na+,K+-ATPase current in the presence of extracellular K+. In contrast, CPZ stimulated pump current in the absence of extracellular K+. Similar conclusions were attained using HEK293 cells loaded with the Na+ sensitive dye Asante NaTRIUM green. Proteolytic cleavage of pig kidney Na+,K+-ATPase indicated that CPZ stabilizes ion interaction with the K+ sites. The distal part of membrane span 10 (M10) of the α-subunit was exposed to trypsin cleavage in the presence of guanidinum ions, which function as Na+ congener at the Na+ specific site. This effect of guanidinium was amplified by treatment with CPZ. Fluorescence of the membrane potential sensitive dye, oxonol VI, was measured following addition of substrates to reconstituted inside-out Na+,K+-ATPase. CPZ increased oxonol VI fluorescence in the absence of K+, reflecting increased Na+ efflux through the pump. Surprisingly, CPZ induced an ATP-independent increase in fluorescence in the presence of high extravesicular K+, likely indicating opening of an intracellular pathway selective for K+. As revealed by the recent crystal structure of the E1.AlF4-.ADP.3Na+ form of the pig kidney Na+,K+-ATPase, movements of M5 of the α-subunit, which regulate ion selectivity, are controlled by the C-terminal tail that extends from M10. We propose that movements of M10 and its cytoplasmic extension is affected by CPZ, thereby regulating ion selectivity and transport through the K+ sites in Na+,K+-ATPase. PMID:24816799

  19. Caveolin-3 Overexpression Attenuates Cardiac Hypertrophy via Inhibition of T-type Ca2+ Current Modulated by Protein Kinase Cα in Cardiomyocytes*

    PubMed Central

    Markandeya, Yogananda S.; Phelan, Laura J.; Woon, Marites T.; Keefe, Alexis M.; Reynolds, Courtney R.; August, Benjamin K.; Hacker, Timothy A.; Roth, David M.; Patel, Hemal H.; Balijepalli, Ravi C.

    2015-01-01

    Pathological cardiac hypertrophy is characterized by subcellular remodeling of the ventricular myocyte with a reduction in the scaffolding protein caveolin-3 (Cav-3), altered Ca2+ cycling, increased protein kinase C expression, and hyperactivation of calcineurin/nuclear factor of activated T cell (NFAT) signaling. However, the precise role of Cav-3 in the regulation of local Ca2+ signaling in pathological cardiac hypertrophy is unclear. We used cardiac-specific Cav-3-overexpressing mice and in vivo and in vitro cardiac hypertrophy models to determine the essential requirement for Cav-3 expression in protection against pharmacologically and pressure overload-induced cardiac hypertrophy. Transverse aortic constriction and angiotensin-II (Ang-II) infusion in wild type (WT) mice resulted in cardiac hypertrophy characterized by significant reduction in fractional shortening, ejection fraction, and a reduced expression of Cav-3. In addition, association of PKCα and angiotensin-II receptor, type 1, with Cav-3 was disrupted in the hypertrophic ventricular myocytes. Whole cell patch clamp analysis demonstrated increased expression of T-type Ca2+ current (ICa, T) in hypertrophic ventricular myocytes. In contrast, the Cav-3-overexpressing mice demonstrated protection from transverse aortic constriction or Ang-II-induced pathological hypertrophy with inhibition of ICa, T and intact Cav-3-associated macromolecular signaling complexes. siRNA-mediated knockdown of Cav-3 in the neonatal cardiomyocytes resulted in enhanced Ang-II stimulation of ICa, T mediated by PKCα, which caused nuclear translocation of NFAT. Overexpression of Cav-3 in neonatal myocytes prevented a PKCα-mediated increase in ICa, T and nuclear translocation of NFAT. In conclusion, we show that stable Cav-3 expression is essential for protecting the signaling mechanisms in pharmacologically and pressure overload-induced cardiac hypertrophy. PMID:26170457

  20. Inhibition of K+ transport through Na+, K+-ATPase by capsazepine: role of membrane span 10 of the α-subunit in the modulation of ion gating.

    PubMed

    Mahmmoud, Yasser A; Shattock, Michael; Cornelius, Flemming; Pavlovic, Davor

    2014-01-01

    Capsazepine (CPZ) inhibits Na+,K+-ATPase-mediated K+-dependent ATP hydrolysis with no effect on Na+-ATPase activity. In this study we have investigated the functional effects of CPZ on Na+,K+-ATPase in intact cells. We have also used well established biochemical and biophysical techniques to understand how CPZ modifies the catalytic subunit of Na+,K+-ATPase. In isolated rat cardiomyocytes, CPZ abolished Na+,K+-ATPase current in the presence of extracellular K+. In contrast, CPZ stimulated pump current in the absence of extracellular K+. Similar conclusions were attained using HEK293 cells loaded with the Na+ sensitive dye Asante NaTRIUM green. Proteolytic cleavage of pig kidney Na+,K+-ATPase indicated that CPZ stabilizes ion interaction with the K+ sites. The distal part of membrane span 10 (M10) of the α-subunit was exposed to trypsin cleavage in the presence of guanidinum ions, which function as Na+ congener at the Na+ specific site. This effect of guanidinium was amplified by treatment with CPZ. Fluorescence of the membrane potential sensitive dye, oxonol VI, was measured following addition of substrates to reconstituted inside-out Na+,K+-ATPase. CPZ increased oxonol VI fluorescence in the absence of K+, reflecting increased Na+ efflux through the pump. Surprisingly, CPZ induced an ATP-independent increase in fluorescence in the presence of high extravesicular K+, likely indicating opening of an intracellular pathway selective for K+. As revealed by the recent crystal structure of the E1.AlF4-.ADP.3Na+ form of the pig kidney Na+,K+-ATPase, movements of M5 of the α-subunit, which regulate ion selectivity, are controlled by the C-terminal tail that extends from M10. We propose that movements of M10 and its cytoplasmic extension is affected by CPZ, thereby regulating ion selectivity and transport through the K+ sites in Na+,K+-ATPase.

  1. Electroacupuncture modulated the inflammatory reaction in MCAO rats via inhibiting the TLR4/NF-κB signaling pathway in microglia

    PubMed Central

    Han, Bingbing; Lu, Yan; Zhao, Haijun; Wang, Yuan; Li, Lin; Wang, Tong

    2015-01-01

    In this study, we aim to investigate the effects of electroacupuncture on the TLR4/NF-κB signaling pathway in microglia. Male Wistar rat of SPF grade (weighing 200±20 g) were randomly divided into (i): sham control group, which was subjected to sham operation (ii) vehicle group, which underwent the occlusion of middle cerebral artery; (iii-v): acupuncture groups, which were subjected to the occlusion of middle cerebral artery and treated with acupuncture on the Neiguan acupoint (P6), Quchi acupoint (LI11), and Diji acupoint (SP8), respectively. HE staining was performed to detect the necrotic rate of neurons. Mediators of inflammation were measured using ELISA. Immunofluorescence was performed to measure the expression of TLR4, HMGB1, TRAF6, IKKβ and NF-κB p65 in microglia. Severe decrease was noticed in the neurological score, necrotic rates of neuron, expression of IL-1β, IL-6, TLR4, HMGB1, TRAF6, IKKβ and NF-κB p65 in microglia. Compared with the vehicle group, significant decrease was revealed in the neurological score, necrotic rate, IL-1β, TLR4, TRAF6, IKKβ and NF-κB p65 in Neiguan group and Quchi group, respectively. In addition, remarkable decrease was observed in the expression of TNF-α and IL-6 in Quchi group. Compared with the Diji group, the necrotic rate of neurons in hippocampus region was significantly decreased in the Quchi group (P < 0.05). In Neiguan group, the expression of TLR4 and IKKβ was significantly attenuated (P < 0.05). The expression of TRAF6 was remarkably decreased in the Neiguan group and Quchi group, respectively. Electroacupuncture on Neiguan and Quchi could improve the neurological injury, attenuate the inflammation, and inhibit the activity of TLR4/NF-κB signaling pathway in microglia. PMID:26617842

  2. NaVβ Subunits Modulate the Inhibition of NaV1.8 by the Analgesic Gating Modifier μO-Conotoxin MrVIB

    PubMed Central

    Wilson, Michael J.; Zhang, Min-Min; Azam, Layla; Olivera, Baldomero M.; Bulaj, Grzegorz

    2011-01-01

    Voltage-gated sodium channels (VGSCs) consist of a pore-forming α-subunit and regulatory β-subunits. Several families of neuroactive peptides of Conus snails target VGSCs, including μO-conotoxins and μ-conotoxins. Unlike μ-conotoxins and the guanidinium alkaloid saxitoxin (STX), which are pore blockers, μO-conotoxins MrVIA and MrVIB inhibit VGSCs by modifying channel gating. μO-MrVIA/B can block NaV1.8 (a tetrodotoxin-resistant isoform of VGSCs) and have analgesic properties. The effect of NaVβ-subunit coexpression on susceptibility to block by μO-MrVIA/B and STX has, until now, not been reported. Here, we show that β1-, β2-, β3-, and β4-subunits, when individually coexpressed with NaV1.8 in Xenopus laevis oocytes, increased the kon of the block produced by μO-MrVIB (by 3-, 32-, 2-, and 7-fold, respectively) and modestly decreased the apparent koff. Strong depolarizing prepulses markedly accelerated MrVIB washout with rates dependent on β-subunit coexpression. Thus, coexpression of β-subunits with NaV1.8 can strongly influence the affinity of the conopeptide for the channel. This observation is of particular interest because β-subunit expression can be dynamic, e.g., β2-expression is up-regulated after nerve injury (J Neurosci, 25:10970–10980, 2005); therefore, the effectiveness of a μO-conotoxin as a channel blocker could be enhanced by the conditions that may call for its use therapeutically. In contrast to MrVIB's action, the STX-induced block of NaV1.8 was only marginally, if at all, affected by coexpression of any of the β-subunits. Our results raise the possibility that μO-conotoxins and perhaps other gating modifiers may provide a means to functionally assess the β-subunit composition of VGSC complexes in neurons. PMID:21586605

  3. XJP-1 protects endothelial cells from oxidized low-density lipoprotein-induced apoptosis by inhibiting NADPH oxidase subunit expression and modulating the PI3K/Akt/eNOS pathway.

    PubMed

    Fu, Rong; Wang, Qiujuan; Guo, Qinglong; Xu, Jinyi; Wu, Xiaoming

    2013-01-01

    Endothelial apoptosis triggered by oxidized low-density lipoprotein (ox-LDL) can accelerate the progression of endothelial dysfunction in atherosclerosis. (±)7,8-Dihydroxy-3-methyl-isochromanone-4 (XJP-1) is a natural phenolic compound derived from banana peel. In the present study, we investigated the anti-apoptotic effect of XJP-1 in human umbilical vein endothelial cells (HUVECs) exposed to ox-LDL and explored underlying mechanisms. Our results showed that in the presence of ox-LDL, XJP-1 significantly attenuated ox-LDL-mediated cytotoxicity, apoptosis, caspase-3 activation, reactive oxygen species (ROS) generation, and NADPH oxidase subunit (p22phox and p47phox) expression in HUVECs. In addition, the anticytotoxic and anti-apoptotic effect of XJP-1 was partially inhibited by a PI3K inhibitor (LY294002), an Akt inhibitor (SH-6), a specific eNOS inhibitor (l-NAME) and a NADPH oxidase inhibitor (DPI). In exploring the underlying mechanisms of XJP-1 action, we found that XJP-1 eliminated ox-LDL-induced dephosphorylation of Akt and eNOS in a dose-dependent manner. However, XJP-1 alone upregulation of Akt and eNOS phosphorylation were blocked by LY294002 and SH-6. Moreover, XJP-1 increased NO production, but this effect was abolished by LY294002, SH-6 and l-NAME. The inhibition of ox-LDL-induced endothelial dysfunction by XJP-1 is due at least in part to its anti-oxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway.

  4. Theiler's virus infection provokes the overexpression of genes coding for the chemokine Ip10 (CXCL10) in SJL/J murine astrocytes, which can be inhibited by modulators of estrogen receptors.

    PubMed

    Rubio, Nazario; Arevalo, Maria-Angeles; Cerciat, Marie; Sanz-Rodriguez, Francisco; Unkila, Mikko; Garcia-Segura, Luis Miguel

    2014-10-01

    Theiler's murine encephalomyelitis virus (TMEV) induces demyelination in susceptible strains of mice (SJL/J) through an immunopathological process that is mediated by CD4(+) Th1 T cell. These T cells are chemoattracted to the central nervous system by chemokines. Hence, in this study, we focused on the production of the chemokine "interferon-gamma-inducible protein 10 kDa," or IP-10/CXCL10, by cultured SJL/J mouse astrocytes infected with the BeAn strain of TMEV and its capacity to attract activated T cells. The analysis of the whole murine genome by DNA hybridization with cRNAs from mock- and TMEV-infected cultures revealed the upregulation of six sequences that potentially encode for CXCL10. This increased CXCL10 expression was validated by PCR and qPCR. The presence of this chemokine was further demonstrated by enzyme-linked immunoassay (ELISA). Significantly, astrocytes from BALB/c mice, a strain resistant to demyelination, did not produce CXCL10. The secreted CXCL10 was biologically active, inducing chemoattraction of activated lymphocytes. The inflammatory cytokines, IL-1α, IFN-γ, and TNF-α, were strong inducers of CXCL10 in astrocytes. Serum from TMEV-infected SJL/J but not BALB/c mice contains CXCL10, the levels of which peak at the onset of the clinical disease. Finally, this in vitro inflammation model was fully inhibited by 17β-estradiol and four selective estrogen receptor modulators, as demonstrated by ELISA and qPCR.

  5. Episodic Inhibition

    ERIC Educational Resources Information Center

    Racsmany, Mihaly; Conway, Martin A.

    2006-01-01

    Six experiments examined the proposal that an item of long-term knowledge can be simultaneously inhibited and activated. In 2 directed forgetting experiments items to-be-forgotten were found to be inhibited in list-cued recall but activated in lexical decision tasks. In 3 retrieval practice experiments, unpracticed items from practiced categories…

  6. Coffee and caffeine potentiate the antiamyloidogenic activity of melatonin via inhibition of Aβ oligomerization and modulation of the Tau-mediated pathway in N2a/APP cells

    PubMed Central

    Zhang, Li-Fang; Zhou, Zhi-Wei; Wang, Zhen-Hai; Du, Yan-Hui; He, Zhi-Xu; Cao, Chuanhai; Zhou, Shu-Feng

    2015-01-01

    . Coff or Caff, plus Mel downregulated Wnt3α expression but upregulated β-catenin. However, Coff or Caff plus Mel did not significantly alter the production of T helper cell (Th)1-related interleukin (IL)-12 and interferon (IFN)-γ and Th2-related IL-4 and IL-10 in N2a/APP cells. The autophagy of cells was not affected by the combinations. Taken together, combination of Caff or Coff, before treatment with Mel elicits an additive antiamyloidogenic effects in N2a/APP cells, probably through inhibition of Aβ oligomerization and modulation of the Akt/GSK3β/Tau signaling pathway. PMID:25565776

  7. Module Configuration

    DOEpatents

    Oweis, Salah; D'Ussel, Louis; Chagnon, Guy; Zuhowski, Michael; Sack, Tim; Laucournet, Gaullume; Jackson, Edward J.

    2002-06-04

    A stand alone battery module including: (a) a mechanical configuration; (b) a thermal management configuration; (c) an electrical connection configuration; and (d) an electronics configuration. Such a module is fully interchangeable in a battery pack assembly, mechanically, from the thermal management point of view, and electrically. With the same hardware, the module can accommodate different cell sizes and, therefore, can easily have different capacities. The module structure is designed to accommodate the electronics monitoring, protection, and printed wiring assembly boards (PWAs), as well as to allow airflow through the module. A plurality of modules may easily be connected together to form a battery pack. The parts of the module are designed to facilitate their manufacture and assembly.

  8. Prostaglandin E2 inhibits α-smooth muscle actin transcription during myofibroblast differentiation via distinct mechanisms of modulation of serum response factor and myocardin-related transcription factor-A.

    PubMed

    Penke, Loka R K; Huang, Steven K; White, Eric S; Peters-Golden, Marc

    2014-06-13

    Differentiation of lung fibroblasts into contractile protein-expressing myofibroblasts by transforming growth factor-β1 (TGF-β1) is a critical event in the pathogenesis of pulmonary fibrosis. Transcription of the contractile protein α-smooth muscle actin (α-SMA) is mediated by the transcription factor serum-response factor (SRF) along with its co-activator, myocardin-related transcription factor-A (MRTF-A). The endogenous lipid mediator prostaglandin E2 (PGE2) exerts anti-fibrotic effects, including the inhibition of myofibroblast differentiation. However, the mechanism by which PGE2 inhibits α-SMA expression is incompletely understood. Here, we show in normal lung fibroblasts that PGE2 reduced the nuclear accumulation of MRTF-A·SRF complexes and consequently inhibited α-SMA promoter activation. It did so both by independently inhibiting SRF gene expression and nuclear import of MRTF-A. We identified that p38 MAPK is critical for TGF-β1-induced SRF gene expression and that PGE2 inhibition of SRF expression is associated with its ability to inhibit p38 activation. Its inhibition of MRTF-A import occurs via activation of cofilin 1 and inactivation of vasodilator-stimulated phosphoprotein. Similar effects of PGE2 on SRF gene expression were observed in fibroblasts from the lungs of patients with idiopathic pulmonary fibrosis. Thus, PGE2 is the first substance described to prevent myofibroblast differentiation by disrupting, via distinct mechanisms, the actions of both SRF and MRTF-A.

  9. Improving the pharmacokinetic and CYP inhibition profiles of azaxanthene-based glucocorticoid receptor modulators-identification of (S)-5-(2-(9-fluoro-2-(4-(2-hydroxypropan-2-yl)phenyl)-5H-chromeno[2,3-b]pyridin-5-yl)-2-methylpropanamido)-N-(tetrahydro-2H-pyran-4-yl)-1,3,4-thiadiazole-2-carboxamide (BMS-341).

    PubMed

    Yang, Michael G; Dhar, T G Murali; Xiao, Zili; Xiao, Hai-Yun; Duan, James J-W; Jiang, Bin; Galella, Michael A; Cunningham, Mark; Wang, Jinhong; Habte, Sium; Shuster, David; McIntyre, Kim W; Carman, Julie; Holloway, Deborah A; Somerville, John E; Nadler, Steven G; Salter-Cid, Luisa; Barrish, Joel C; Weinstein, David S

    2015-05-28

    An empirical approach to improve the microsomal stability and CYP inhibition profile of lead compounds 1a and 1b led to the identification of 5 (BMS-341) as a dissociated glucocorticoid receptor modulator. Compound 5 showed significant improvements in pharmacokinetic properties and, unlike compounds 1a-b, displayed a linear, dose-dependent pharmacokinetic profile in rats. When tested in a chronic model of adjuvant-induced arthritis in rat, the ED50 of 5 (0.9 mg/kg) was superior to that of both 1a and 1b (8 and 17 mg/kg, respectively). PMID:25905990

  10. Chlorogenic acid induces apoptosis to inhibit inflammatory proliferation of IL-6-induced fibroblast-like synoviocytes through modulating the activation of JAK/STAT and NF-κB signaling pathways

    PubMed Central

    LOU, LIXIA; ZHOU, JINGWEI; LIU, YUJUN; WEI, YI; ZHAO, JIULI; DENG, JIAGANG; DONG, BIN; ZHU, LINGQUN; WU, AIMING; YANG, YINGXI; CHAI, LIMIN

    2016-01-01

    Chlorogenic acid (CGA) is the primary constituent of Caulis Lonicerae, a Chinese herb used for the treatment of rheumatoid arthritis (RA). The present study aimed to investigate whether CGA was able to inhibit the proliferation of the fibroblast-like synoviocyte cell line (RSC-364), stimulated by interleukin (IL)-6, through inducing apoptosis. Following incubation with IL-6 or IL-6 and CGA, the cellular proliferation of RSC-364 cells was detected by MTT assay. The ratio of apoptosed cells were detected by flow cytometry. Western blot analysis was performed to observe protein expression levels of key molecules involved in the Janus-activated kinase/signal transducer and activator of transcription 3 (JAK/STAT) signaling pathway [phosphorylated (p)-STAT3, JAK1 and gp130] and the nuclear factor κB (NF-κB) signaling pathway [phosphorylated (p)-inhibitor of κB kinase subunit α/β and NF-κB p50). It was revealed that CGA was able to inhibit the inflammatory proliferation of RSC-364 cells mediated by IL-6 through inducing apoptosis. CGA was also able to suppress the expression levels of key molecules in the JAK/STAT and NF-κB signaling pathways, and inhibit the activation of these signaling pathways in the inflammatory response through IL-6-mediated signaling, thereby resulting in the inhibition of the inflammatory proliferation of synoviocytes. The present results indicated that CGA may have potential as a novel therapeutic agent for inhibiting inflammatory hyperplasia of the synovium through inducing synoviocyte apoptosis in patients with RA. PMID:27168850

  11. Nicotinic α7 receptor inhibits the acylation stimulating protein-induced production of monocyte chemoattractant protein-1 and keratinocyte-derived chemokine in adipocytes by modulating the p38 kinase and nuclear factor-κB signaling pathways

    PubMed Central

    Jiao, Zhou-Yang; Wu, Jing; Liu, Chao; Wen, Bing; Zhao, Wen-Zeng; Du, Xin-Ling

    2016-01-01

    Obesity is associated with chronic low-grade inflammation, which is characterized by increased infiltration of macrophages into adipose tissue. Acylation stimulating protein (ASP) is an adipokine derived from the immune complement system, which constitutes a link between adipocytes and macrophages, and is involved in energy homeostasis and inflammation. The purpose of the present study was to preliminarily investigate in vitro, whether functional α7nAChR in adipocytes may suppress ASP-induced inflammation and determine the possible signaling mechanism. Studies have reported associations between the expression of α7 nicotinic acetylcholine receptor (α7nAChR) and obesity, insulin resistance and diabetes. Additionally, α7nAChRs are important peripheral mediators of chronic inflammation, which is a key contributor to health problems in obesity. The primary aim of the present study was to evaluate the impact of exogenous ASP and α7nAChR on macrophage infiltration in adipose tissue and to examine the potential underlying molecular mechanism. Western blot analysis revealed that recombinant ASP increased the expression levels of monocyte chemoattractant protein-1 (MCP-1) and keratinocyte-derived chemokine (KC) by 3T3-L1 adipocytes. However, nicotine significantly inhibited the production of ASP-induced cytokines via the stimulation of α7nAChR. It was also found that α7nAChR inhibited the ASP-induced activation of p38 kinase and nuclear factor-κB (NF-κB), and the production of MCP-1 and KC. These data indicated that α7nAChR caused the inhibition of ASP-induced activation of p38 kinase and NF-κB to inhibit the production of MCP-1 and KC. PMID:27572255

  12. Nicotinic α7 receptor inhibits the acylation stimulating protein‑induced production of monocyte chemoattractant protein‑1 and keratinocyte‑derived chemokine in adipocytes by modulating the p38 kinase and nuclear factor‑κB signaling pathways.

    PubMed

    Jiao, Zhou-Yang; Wu, Jing; Liu, Chao; Wen, Bing; Zhao, Wen-Zeng; Du, Xin-Ling

    2016-10-01

    Obesity is associated with chronic low‑grade inflammation, which is characterized by increased infiltration of macrophages into adipose tissue. Acylation stimulating protein (ASP) is an adipokine derived from the immune complement system, which constitutes a link between adipocytes and macrophages, and is involved in energy homeostasis and inflammation. The purpose of the present study was to preliminarily investigate in vitro, whether functional α7nAChR in adipocytes may suppress ASP‑induced inflammation and determine the possible signaling mechanism. Studies have reported associations between the expression of α7 nicotinic acetylcholine receptor (α7nAChR) and obesity, insulin resistance and diabetes. Additionally, α7nAChRs are important peripheral mediators of chronic inflammation, which is a key contributor to health problems in obesity. The primary aim of the present study was to evaluate the impact of exogenous ASP and α7nAChR on macrophage infiltration in adipose tissue and to examine the potential underlying molecular mechanism. Western blot analysis revealed that recombinant ASP increased the expression levels of monocyte chemoattractant protein‑1 (MCP‑1) and keratinocyte‑derived chemokine (KC) by 3T3‑L1 adipocytes. However, nicotine significantly inhibited the production of ASP‑induced cytokines via the stimulation of α7nAChR. It was also found that α7nAChR inhibited the ASP‑induced activation of p38 kinase and nuclear factor‑κB (NF‑κB), and the production of MCP‑1 and KC. These data indicated that α7nAChR caused the inhibition of ASP‑induced activation of p38 kinase and NF‑κB to inhibit the production of MCP‑1 and KC. PMID:27572255

  13. Nicotinic α7 receptor inhibits the acylation stimulating protein‑induced production of monocyte chemoattractant protein‑1 and keratinocyte‑derived chemokine in adipocytes by modulating the p38 kinase and nuclear factor‑κB signaling pathways.

    PubMed

    Jiao, Zhou-Yang; Wu, Jing; Liu, Chao; Wen, Bing; Zhao, Wen-Zeng; Du, Xin-Ling

    2016-10-01

    Obesity is associated with chronic low‑grade inflammation, which is characterized by increased infiltration of macrophages into adipose tissue. Acylation stimulating protein (ASP) is an adipokine derived from the immune complement system, which constitutes a link between adipocytes and macrophages, and is involved in energy homeostasis and inflammation. The purpose of the present study was to preliminarily investigate in vitro, whether functional α7nAChR in adipocytes may suppress ASP‑induced inflammation and determine the possible signaling mechanism. Studies have reported associations between the expression of α7 nicotinic acetylcholine receptor (α7nAChR) and obesity, insulin resistance and diabetes. Additionally, α7nAChRs are important peripheral mediators of chronic inflammation, which is a key contributor to health problems in obesity. The primary aim of the present study was to evaluate the impact of exogenous ASP and α7nAChR on macrophage infiltration in adipose tissue and to examine the potential underlying molecular mechanism. Western blot analysis revealed that recombinant ASP increased the expression levels of monocyte chemoattractant protein‑1 (MCP‑1) and keratinocyte‑derived chemokine (KC) by 3T3‑L1 adipocytes. However, nicotine significantly inhibited the production of ASP‑induced cytokines via the stimulation of α7nAChR. It was also found that α7nAChR inhibited the ASP‑induced activation of p38 kinase and nuclear factor‑κB (NF‑κB), and the production of MCP‑1 and KC. These data indicated that α7nAChR caused the inhibition of ASP‑induced activation of p38 kinase and NF‑κB to inhibit the production of MCP‑1 and KC.

  14. Firefighting Module

    NASA Astrophysics Data System (ADS)

    1981-01-01

    Aviation Power Supply's mobile firefighting module called Firefly II is mounted on a trailer pulled by a pickup truck. Trailer unit has two three- inch water cannons, and the pickup carries a six inch cannon. Completely self contained, module pumps 3,000 gallons of water a minute from hydrants or open bodies of water. Stream can go as far as 400 feet or can be employed in a high-loft mode to reach the tops of tall refinery towers. Compact Firefly II weighs only 2,500 pounds when fully fueled. Key component is a specially designed two stage pump. Power for the pump is generated by a gas turbine engine. Module also includes an electronic/pump controller, multiple hose connections, up to 1,500 feet of hose and fuel for four hours operation. Firefly trailer can be backed onto specially-built large fireboat.

  15. Firefighting Module

    NASA Astrophysics Data System (ADS)

    1980-01-01

    Aviation Power Supply's mobile firefighting module called Firefly II is mounted on a trailer pulled by a pickup truck. Trailer unit has two three- inch water cannons, and the pickup carries a six inch cannon. Completely self contained, module pumps 3,000 gallons of water a minute from hydrants or open bodies of water. Stream can go as far as 400 feet or can be employed in a high-loft mode to reach the tops of tall refinery towers. Compact Firefly II weighs only 2,500 pounds when fully fueled. Key component is a specially designed two stage pump. Power for the pump is generated by a gas turbine engine. Module also includes an electronic/pump controller, multiple hose connections, up to 1,500 feet of hose and fuel for four hours operation. Firefly trailer can be backed onto specially-built large fireboat.

  16. Photodynamic immune modulation (PIM)

    NASA Astrophysics Data System (ADS)

    North, John R.; Hunt, David W. C.; Simkin, Guillermo O.; Ratkay, Leslie G.; Chan, Agnes H.; Lui, Harvey; Levy, Julia G.

    1999-09-01

    Photodynamic Therapy (PDT) is accepted for treatment of superficial and lumen-occluding tumors in regions accessible to activating light and is now known to be effective in closure of choroidal neovasculature in Age Related Macular Degeneration. PDT utilizes light absorbing drugs (photosensitizers) that generate the localized formation of reactive oxygen species after light exposure. In a number of systems, PDT has immunomodulatory effects; Photodynamic Immune Modulation (PIM). Using low- intensity photodynamic regimens applied over a large body surface area, progression of mouse autoimmune disease could be inhibited. Further, this treatment strongly inhibited the immunologically- medicated contact hypersensitivity response to topically applied chemical haptens. Immune modulation appears to result from selective targeting of activated T lymphocytes and reduction in immunostimulation by antigen presenting cells. Psoriasis, an immune-mediated skin condition, exhibits heightened epidermal cell proliferation, epidermal layer thickening and plaque formation at different body sites. In a recent clinical trial, approximately one-third of patients with psoriasis and arthritis symptoms (psoriatic arthritis) displayed a significant clinical improvement in several psoriasis-related parameters after four weekly whole-body PIM treatments with verteporfin. The safety profile was favorable. The capacity of PIM to influence other human immune disorders including rheumatoid arthritis is under extensive evaluation.

  17. Thermionic modules

    DOEpatents

    King, Donald B.; Sadwick, Laurence P.; Wernsman, Bernard R.

    2002-06-18

    Modules of assembled microminiature thermionic converters (MTCs) having high energy-conversion efficiencies and variable operating temperatures manufactured using MEMS manufacturing techniques including chemical vapor deposition. The MTCs incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. The MTCs also exhibit maximum efficiencies of just under 30%, and thousands of the devices and modules can be fabricated at modest costs.

  18. Modulation of in vitro monocyte cytokine responses to Leishmania donovani. Interferon-gamma prevents parasite-induced inhibition of interleukin 1 production and primes monocytes to respond to Leishmania by producing both tumor necrosis factor-alpha and interleukin 1.

    PubMed Central

    Reiner, N E; Ng, W; Wilson, C B; McMaster, W R; Burchett, S K

    1990-01-01

    Cytokines produced by mononuclear cells are important regulatory and effector molecules and evidence has been presented to support a role at least for tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in host defense against Leishmania. In the present study, we examined the production of TNF-alpha and interleukin 1 (IL-1) by resting and IFN-gamma-primed peripheral blood monocytes infected in vitro with Leishmania donovani. Monocytes produced neither IL-1 nor TNF-alpha during challenge with Leishmania. Cells preinfected with Leishmania synthesized normal amounts of TNF-alpha, but had diminished production of IL-1 in response to stimulation with either S. aureus or lipopolysaccharide (LPS). The induction by S. aureus or LPS of IL-1 beta mRNA accumulation in infected cells was normal despite diminished intracellular or supernatant IL-1 protein and bioactivity. Thus, inhibition of IL-1 production by Leishmania most probably reflected diminished translation of IL-1 beta mRNA. Pretreatment of cells with IFN-gamma abrogated infection-induced inhibition of IL-1 production and primed cells for the production of both IL-1 and TNF-alpha upon subsequent exposure to Leishmania. These results indicate that L. donovani has evolved the capacity to infect mononuclear phagocytes, without stimulating the production of two potentially host-protective monokines. The ability of IFN-gamma to prime monocytes to produce TNF-alpha and IL-1 in response to infection with Leishmania and to prevent inhibition of IL-1 production may have implications for immunotherapy with this lymphokine. Images PMID:2112157

  19. Scopoletin, an active principle of tree tobacco (Nicotiana glauca) inhibits human tumor vascularization in xenograft models and modulates ERK1, VEGF-A, and FGF-2 in computer model.

    PubMed

    Tabana, Yasser M; Hassan, Loiy Elsir A; Ahamed, Mohamed B Khadeer; Dahham, Saad S; Iqbal, Muhammad Adnan; Saeed, Mohammed A A; Khan, Md Shamsuddin S; Sandai, Doblin; Majid, Aman S Abdul; Oon, Chern Ein; Majid, Amin Malik S A

    2016-09-01

    We recently reported the antineovascularization effect of scopoletin on rat aorta and identified its potential anti-angiogenic activity. Scopoletin could be useful as a systemic chemotherapeutic agent against angiogenesis-dependent malignancies if its antitumorigenic activity is investigated and scientifically proven using a suitable human tumor xenograft model. In the present study, bioassay-guided (anti-angiogenesis) phytochemical investigation was conducted on Nicotiana glauca extract which led to the isolation of scopoletin. Further, anti-angiogenic activity of scopoletin was characterized using ex vivo, in vivo and in silico angiogenesis models. Finally, the antitumorigenic efficacy of scopoletin was studied in human colorectal tumor xenograft model using athymic nude mice. For the first time, an in vivo anticancer activity of scopoletin was reported and characterized using xenograft models. Scopoletin caused significant suppression of sprouting of microvessels in rat aortic explants with IC50 (median inhibitory concentration) 0.06μM. Scopoletin (100 and 200mg/kg) strongly inhibited (59.72 and 89.4%, respectively) vascularization in matrigel plugs implanted in nude mice. In the tumor xenograft model, scopoletin showed remarkable inhibition on tumor growth (34.2 and 94.7% at 100 and 200mg/kg, respectively). Tumor histology revealed drastic reduction of the extent of vascularization. Further, immunostaining of CD31 and NG2 receptors in the histological sections confirmed the antivascular effect of scopoletin in tumor vasculature. In computer modeling, scopoletin showed strong ligand affinity and binding energies toward the following angiogenic factors: protein kinase (ERK1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2). These results suggest that the antitumor activity of scopoletin may be due to its strong anti-angiogenic effect, which may be mediated by its effective inhibition of ERK1, VEGF-A, and FGF-2. PMID:27133199

  20. Ubiquilin-2 (UBQLN2) binds with high affinity to the C-terminal region of TDP-43 and modulates TDP-43 levels in H4 cells: characterization of inhibition by nucleic acids and 4-aminoquinolines.

    PubMed

    Cassel, Joel A; Reitz, Allen B

    2013-06-01

    Recently, it was reported that mutations in the ubiquitin-like protein ubiquilin-2 (UBQLN2) are associated with X-linked amyotrophic lateral sclerosis (ALS), and that both wild-type and mutant UBQLN2 can co-localize with aggregates of C-terminal fragments of TAR DNA binding protein (TDP-43). Here, we describe a high affinity interaction between UBQLN2 and TDP-43 and demonstrate that overexpression of both UBQLN2 and TDP-43 reduces levels of both exogenous and endogenous TDP-43 in human H4 cells. UBQLN2 bound with high affinity to both full length TDP-43 and a C-terminal TDP-43 fragment (261-414 aa) with KD values of 6.2nM and 8.7nM, respectively. Both DNA oligonucleotides and 4-aminoquinolines, which bind to TDP-43, also inhibited UBQLN2 binding to TDP-43 with similar rank order affinities compared to inhibition of oligonucleotide binding to TDP-43. Inhibitor characterization experiments demonstrated that the DNA oligonucleotides noncompetitively inhibited UBQLN2 binding to TDP-43, which is consistent with UBQLN2 binding to the C-terminal region of TDP-43. Interestingly, the 4-aminoquinolines were competitive inhibitors of UBQLN2 binding to TDP-43, suggesting that these compounds also bind to the C-terminal region of TDP-43. In support of the biochemical data, co-immunoprecipitation experiments demonstrated that both TDP-43 and UBQLN2 interact in human neuroglioma H4 cells. Finally, overexpression of UBQLN2 in the presence of overexpressed full length TDP-43 or C-terminal TDP-43 (170-414) dramatically lowered levels of both full length TDP-43 and C-terminal TDP-43 fragments (CTFs). Consequently, these data suggest that UBQLN2 enhances the clearance of TDP-43 and TDP-43 CTFs and therefore may play a role in the development of TDP-43 associated neurotoxicity.

  1. Antitumor effect of a selective COX-2 inhibitor, celecoxib, may be attributed to angiogenesis inhibition through modulating the PTEN/PI3K/Akt/HIF-1 pathway in an H₂₂ murine hepatocarcinoma model.

    PubMed

    Sui, Wenwen; Zhang, Yueying; Wang, Zhaopeng; Wang, Zhaoxia; Jia, Qing; Wu, Licun; Zhang, Weidong

    2014-05-01

    Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, has recently been shown to affect the development of different types of cancer. The present study utilized a murine H22 hepatocarcinoma model to investigate the molecular mechanisms involved in celecoxib-induced inhibition of tumor angiogenesis. Tumor-bearing mice were randomly divided into five groups: i) control; ii) low-dose celecoxib (50 mg/kg); iii) high-dose celecoxib (200 mg/kg); iv) 5-fluorouracil (5-FU), (20 mg/kg) and v) combination of 5-FU and celecoxib (50 mg/kg). The antitumor effect of celecoxib was determined by measuring tumor volume. Tumor angiogenesis was evaluated by microvessel density (MVD). Tumor histology and immunostaining for CD34 in endothelial cells were performed to detect MVD. The expression levels of phosphatase and tensin homologue deleted from chromosome 10 (PTEN), phosphatidylinositol 3-kinase (PI3K), phospho‑Akt (P-Akt), COX-2, hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor-A (VEGF-A) were detected by ELISA, immunohistochemistry and western blotting, respectively. We discovered substantial growth delay in murine H22 hepatoma as a result of celecoxib treatment. The inhibition rate of tumor growth induced by high-dose and low-dose celecoxib was 49.3 and 37.0%, respectively (P<0.05). The expression of PI3K, P-Akt, COX-2, HIF-1α, VEGF-A and PTEN in tumor tissues treated with celecoxib was demonstrated by immunohistochemistry, and the MVD was decreased in a dose-dependent manner (P<0.05). Reduced PI3K and P-Akt was particularly apparent in the high-dose celecoxib group (P<0.05). ELISA and western blotting data showed that the expression of PI3K, P-Akt, COX-2, HIF-1α and VEGF-A were reduced and PTEN was increased after treatment with celecoxib. In conclusion, the impact of celecoxib-induced tumor growth delay of murine H22 hepatocarcinoma may correlate with the inhibition of angiogenesis by reducing PI3K, P-Akt, COX-2, HIF-1α and VEGF

  2. Firefighting Module

    NASA Astrophysics Data System (ADS)

    1984-01-01

    Firefly II pump module is NASA's Marshall Space Flight Center's commercial offshoot of a NASA/US Coast Guard program involving development of a lightweight, helicopter-transportable firefighting module for a quick response in combating shipboard or harbor fires. Operable on land or water, the Amphib One is equipped with 3 water cannons. When all 3 are operating, unit pumps more than 3,000 gallons a minute. Newly developed model used by U.S. Coast Guard can pump 5,000 gallons per minute. It was designed for applications such as firefighting onboard ship fires, emergency dockside water pumping, dewatering ships in danger of sinking, flood control, and emergency water supply at remote locations.

  3. Growth inhibition and regression of lung tumors by silibinin: modulation of angiogenesis by macrophage-associated cytokines and nuclear factor-kappaB and signal transducers and activators of transcription 3.

    PubMed

    Tyagi, Alpna; Singh, Rana P; Ramasamy, Kumaraguruparan; Raina, Komal; Redente, Elizabeth F; Dwyer-Nield, Lori D; Radcliffe, Richard A; Malkinson, Alvin M; Agarwal, Rajesh

    2009-01-01

    The latency period for lung tumor progression offers a window of opportunity for therapeutic intervention. Herein, we studied the effect of oral silibinin (742 mg/kg body weight, 5 d/wk for 10 weeks) on the growth and progression of established lung adenocarcinomas in A/J mice. Silibinin strongly decreased both tumor number and tumor size, an antitumor effect that correlates with reduced antiangiogenic activity. Silibinin reduced microvessel size (50%, P < 0.01) with no change in the number of tumor microvessels and reduced (by 30%, P < 0.05) the formation of nestin-positive microvessels in tumors. Analysis of several proteins involved in new blood vessel formation showed that silibinin decreased the tumor expression of interleukin-13 (47%) and tumor necrosis factor-alpha (47%), and increased tissue inhibitor of metalloproteinase-1 (2-fold) and tissue inhibitor of metalloproteinase-2 (7-fold) expression, without significant changes in vascular endothelial growth factor levels. Hypoxia- inducible factor-1 alpha expression and nuclear localization were also decreased by silibinin treatment. Cytokines secreted by tumor cells and tumor-associated macrophages regulate angiogenesis by activating nuclear factor-kappaB (NF-kappaB) and signal transducers and activators of transcription (STAT). Silibinin decreased the phosphorylation of p65NF-kappaB (ser276, 38%; P < 0.01) and STAT-3 (ser727, 16%; P < 0.01) in tumor cells and decreased the lung macrophage population. Angiopoietin-2 (Ang-2) and Ang-receptor tyrosine kinase (Tie-2) expression were increased by silibinin. Therapeutic efficacy of silibinin in lung tumor growth inhibition and regression by antiangiogenic mechanisms seem to be mediated by decreased tumor-associated macrophages and cytokines, inhibition of hypoxia-inducible factor-1 alpha, NF-kappaB, and STAT-3 activation, and up-regulation of the angiogenic inhibitors, Ang-2 and Tie-2.

  4. Thermoelectric module

    DOEpatents

    Kortier, William E.; Mueller, John J.; Eggers, Philip E.

    1980-07-08

    A thermoelectric module containing lead telluride as the thermoelectric mrial is encapsulated as tightly as possible in a stainless steel canister to provide minimum void volume in the canister. The lead telluride thermoelectric elements are pressure-contacted to a tungsten hot strap and metallurgically bonded at the cold junction to iron shoes with a barrier layer of tin telluride between the iron shoe and the p-type lead telluride element.

  5. Linear modulator

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A study of frequency division multiplexing (FDM) systems was made for the purpose of determining the system performance that can be obtained with available state of the art components. System performance was evaluated on the basis of past experience, system analysis, and component evaluation. The system study was specifically directed to the area of FDM systems using subcarrier channel frequencies from 4 kHz to 200 kHz and channel information bandwidths of dc to 1, 2, 4, 8, and 16 kHz. The evaluation also assumes that the demodulation will be from a tape recorder which produces frequency modulation of + or - 1% on the signal due to the tape recorder wow and flutter. For the modulation system it is assumed that the pilot and carrier channel frequencies are stable to within + or - .005% and that the FM on the channel carriers is negligible. The modulator system was evaluated for the temperature range of -20 degree to +85 degree while the demodulator system was evaluated for operation at room temperature.

  6. Designed Proteins To Modulate Cellular Networks

    PubMed Central

    Cortajarena, Aitziber L.; Liu, Tina Y.; Hochstrasser, Mark; Regan, Lynne

    2012-01-01

    A major challenge of protein design is to create useful new proteins that interact specifically with biological targets in living cells. Such binding modules have many potential applications, including the targeted perturbation of protein networks. As a general approach to create such modules, we designed a library with approximately 109 different binding specificities based on a small 3-tetratricopeptide repeat (TPR) motif framework. We employed a novel strategy, based on split GFP reassembly, to screen the library for modules with the desired binding specificity. Using this approach, we identified modules that bind tightly and specifically to Dss1, a small human protein that interacts with the tumor suppressor protein BRCA2. We showed that these modules also bind the yeast homologue of Dss1, Sem1. Furthermore, we demonstrated that these modules inhibit Sem1 activity in yeast. This strategy will be generally applicable to make novel genetically encoded tools for systems/synthetic biology applications. PMID:20020775

  7. Substrate inhibition competes with halide inhibition in polyphenol oxidase.

    PubMed

    Lim, Giselle Grace Fernando; Imura, Yuki; Yoshimura, Etsuro

    2012-10-01

    Polyphenol oxidase (PPO) is a ubiquitous enzyme important in the food industry. Although PPO activity followed Michaelis-Menten kinetics at catechol concentrations of up to 1 mM, it slowly decreased at catechol concentrations above 2 mM. This result indicated that in addition to the active site (site A), the enzyme possesses a second catechol-binding site (site B) that exerts an inhibitory effect on PPO activity. Halides inhibit PPO activity in such a way that substrate inhibition is lessened when halide concentration is increased. Furthermore, elevated concentrations of catechol diminished the degree of inhibition by halides. These findings suggest that halides also bind to site B to inhibit PPO activity. A steady-state kinetic analysis demonstrated that the dissociation constant between catechol and PPO depended on the binding of halides to site B. The dissociation constants were greatest when chloride bound to the site. Bromide and iodide yielded lower dissociation constants, in that order. These data indicate that the binding of halide to site B modulated the structure of site A, thereby exerting an inhibitory effect.

  8. Photovoltaic module and module arrays

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Lenox, Carl J. S.; Culligan, Matthew; Danning, Matt

    2013-08-27

    A photovoltaic (PV) module including a PV device and a frame, The PV device has a PV laminate defining a perimeter and a major plane. The frame is assembled to and encases the laminate perimeter, and includes leading, trailing, and side frame members, and an arm that forms a support face opposite the laminate. The support face is adapted for placement against a horizontal installation surface, to support and orient the laminate in a non-parallel or tilted arrangement. Upon final assembly, the laminate and the frame combine to define a unitary structure. The frame can orient the laminate at an angle in the range of 3.degree.-7.degree. from horizontal, and can be entirely formed of a polymeric material. Optionally, the arm incorporates integral feature(s) that facilitate interconnection with corresponding features of a second, identically formed PV module.

  9. Photovoltaic module and module arrays

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Lenox, Carl J. S.; Culligan, Matthew; Danning, Matt

    2012-07-17

    A photovoltaic (PV) module including a PV device and a frame. The PV device has a PV laminate defining a perimeter and a major plane. The frame is assembled to and encases the laminate perimeter, and includes leading, trailing, and side frame members, and an arm that forms a support face opposite the laminate. The support face is adapted for placement against a horizontal installation surface, to support and orient the laminate in a non-parallel or tilted arrangement. Upon final assembly, the laminate and the frame combine to define a unitary structure. The frame can orient the laminate at an angle in the range of 3.degree.-7.degree. from horizontal, and can be entirely formed of a polymeric material. Optionally, the arm incorporates integral feature(s) that facilitate interconnection with corresponding features of a second, identically formed PV module.

  10. SIRT1-related inhibition of pro-inflammatory responses and oxidative stress are involved in the mechanism of nonspecific low back pain relief after exercise through modulation of Toll-like receptor 4.

    PubMed

    Cheng, Yuan-Yang; Kao, Chung-Lan; Ma, Hsin-I; Hung, Ching-Hsia; Wang, Chin-Tien; Liu, Ding-Hao; Chen, Po-Yin; Tsai, Kun-Ling

    2015-10-01

    Low back pain is a common clinical problem that causes disability and impaired quality of life. While the reason behind low back pain was largely considered to be of musculoskeletal origin, the contribution of inflammatory cytokines and oxidative stress could never be overlooked. Exercise has been proven to be an effective approach to treat low back pain. However, the mechanism of the exercise effect on the inflammatory cytokines and oxidative stress is still largely unknown. In this study, we revealed that exercise intervention reduces Toll-like receptor 4 (TLR-4) pathway and enhances Sirtuin 1 (SIRT1) expression in low back pain patients. We also confirmed that exercise up-regulates the expression of peroxisome proliferator-activated receptor-gamma, PPAR-γ coactivator-1 and FoxOs family proteins and also increases the activity of catalase and superoxide dismutase in patients with low back pain. Furthermore, we found that exercise intervention attenuates the oxidative stress, pro-inflammatory cytokine concentrations and p53 expression in patients with low back pain. This study demonstrates that exercise intervention improves low back pain symptoms through regulation of the SIRT1 axis with repression of oxidative stress and TLR-4 inhibition. PMID:25922201

  11. SIRT1-related inhibition of pro-inflammatory responses and oxidative stress are involved in the mechanism of nonspecific low back pain relief after exercise through modulation of Toll-like receptor 4.

    PubMed

    Cheng, Yuan-Yang; Kao, Chung-Lan; Ma, Hsin-I; Hung, Ching-Hsia; Wang, Chin-Tien; Liu, Ding-Hao; Chen, Po-Yin; Tsai, Kun-Ling

    2015-10-01

    Low back pain is a common clinical problem that causes disability and impaired quality of life. While the reason behind low back pain was largely considered to be of musculoskeletal origin, the contribution of inflammatory cytokines and oxidative stress could never be overlooked. Exercise has been proven to be an effective approach to treat low back pain. However, the mechanism of the exercise effect on the inflammatory cytokines and oxidative stress is still largely unknown. In this study, we revealed that exercise intervention reduces Toll-like receptor 4 (TLR-4) pathway and enhances Sirtuin 1 (SIRT1) expression in low back pain patients. We also confirmed that exercise up-regulates the expression of peroxisome proliferator-activated receptor-gamma, PPAR-γ coactivator-1 and FoxOs family proteins and also increases the activity of catalase and superoxide dismutase in patients with low back pain. Furthermore, we found that exercise intervention attenuates the oxidative stress, pro-inflammatory cytokine concentrations and p53 expression in patients with low back pain. This study demonstrates that exercise intervention improves low back pain symptoms through regulation of the SIRT1 axis with repression of oxidative stress and TLR-4 inhibition.

  12. Sticky Plans: Inhibition and Binding during Serial-Task Control

    ERIC Educational Resources Information Center

    Mayr, Ulrich

    2009-01-01

    Recent evidence suggests substantial response-time costs associated with lag-2 repetitions of tasks within explicitly controlled task sequences [Koch, I., Philipp, A. M., Gade, M. (2006). Chunking in task sequences modulates task inhibition. "Psychological Science," 17, 346-350; Schneider, D. W. (2007). Task-set inhibition in chunked task…

  13. Firing regulation of fast-spiking interneurons by autaptic inhibition

    NASA Astrophysics Data System (ADS)

    Guo, Daqing; Chen, Mingming; Perc, Matjaž; Wu, Shengdun; Xia, Chuan; Zhang, Yangsong; Xu, Peng; Xia, Yang; Yao, Dezhong

    2016-05-01

    Fast-spiking (FS) interneurons in the brain are self-innervated by powerful inhibitory GABAergic autaptic connections. By computational modelling, we investigate how autaptic inhibition regulates the firing response of such interneurons. Our results indicate that autaptic inhibition both boosts the current threshold for action potential generation and modulates the input-output gain of FS interneurons. The autaptic transmission delay is identified as a key parameter that controls the firing patterns and determines multistability regions of FS interneurons. Furthermore, we observe that neuronal noise influences the firing regulation of FS interneurons by autaptic inhibition and extends their dynamic range for encoding inputs. Importantly, autaptic inhibition modulates noise-induced irregular firing of FS interneurons, such that coherent firing appears at an optimal autaptic inhibition level. Our results reveal the functional roles of autaptic inhibition in taming the firing dynamics of FS interneurons.

  14. A Rosemary Extract Rich in Carnosic Acid Selectively Modulates Caecum Microbiota and Inhibits β-Glucosidase Activity, Altering Fiber and Short Chain Fatty Acids Fecal Excretion in Lean and Obese Female Rats

    PubMed Central

    Larrosa, Mar; Obiol, María; García-Villalba, Rocío; González-Barrio, Rocío; Issaly, Nicolas; Flanagan, John; Roller, Marc; Tomás-Barberán, Francisco A.; García-Conesa, María-Teresa

    2014-01-01

    Background Carnosic acid (CA) and rosemary extracts (RE) show body-weight, energy metabolism and inflammation regulatory properties in animal models but the mechanisms are not yet understood. Gut microbiota plays an important role in the host metabolism and inflammatory status and is modulated by the diet. The aim of this research was to investigate whether a RE enriched in CA affected caecum microbiota composition and activity in a rat model of genetic obesity. Methods and Principal Findings A RE (40% CA) was administered with the diet (0.5% w/w) to lean (fa/+) and obese (fa/fa) female Zucker rats for 64 days. Changes in the microbiota composition and β-glucosidase activity in the caecum and in the levels of macronutrients and short chain fatty acids (SCFA) in feces were examined. The RE increased the Blautia coccoides and Bacteroides/Prevotella groups and reduced the Lactobacillus/Leuconostoc/Pediococccus group in both types of animals. Clostridium leptum was significantly decreased and Bifidobacterium increased only in the lean rats. β-Glucosidase activity was significantly reduced and fecal fiber excretion increased in the two genotypes. The RE also increased the main SCFA excreted in the feces of the obese rats but decreased them in the lean rats reflecting important differences in the uptake and metabolism of these molecules between the two genotypes. Conclusions Our results indicate that the consumption of a RE enriched in CA modifies microbiota composition and decreases β-glucosidase activity in the caecum of female Zucker rats while it increases fiber fecal elimination. These results may contribute to explain the body weight gain reducing effects of the RE. The mutated leptin receptor of the obese animals significantly affects the microbiota composition, the SCFA fecal excretion and the host response to the RE intake. PMID:24733124

  15. Salicortin-derivatives from Salix pseudo-lasiogyne twigs inhibit adipogenesis in 3T3-L1 cells via modulation of C/EBPα and SREBP1c dependent pathway.

    PubMed

    Lee, Mina; Lee, Sang Hoon; Kang, Jimmy; Yang, Heejung; Jeong, Eun Ju; Kim, Hong Pyo; Kim, Young Choong; Sung, Sang Hyun

    2013-08-30

    Obesity is reported to be associated with excessive growth of adipocyte mass tissue as a result of increases in the number and size of adipocytes differentiated from preadipocytes. To search for anti-adipogenic phytochemicals, we screened for inhibitory activities of various plant sources on adipocyte differentiation in 3T3-L1 preadipocytes. Among the sources, a methanolic extract of Salix pseudo-lasiogyne twigs (Salicaceae) reduced lipid accumulation in a concentration-dependent manner. During our search for anti-adipogenic constituents from S. pseudo-lasiogyne, five salicortin derivatives isolated from an EtOAc fraction of this plant and bearing 1-hydroxy-6-oxo-2-cyclohexene-carboxylate moieties, namely 2',6'-O-acetylsalicortin (1), 2'-O-acetylsalicortin (2), 3'-O-acetylsalicortin (3), 6'-O-acetylsalicortin (4), and salicortin (5), were found to significantly inhibit adipocyte differentiation in 3T3-L1 cells. In particular, 2',6'-O-acetylsalicortin (1) had the most potent inhibitory activity on adipocyte differentiation, with an IC₅₀ value of 11.6 μM, and it significantly down-regulated the expressions of CCAAT/enhancer binding protein α (C/EBPα) and sterol regulatory element binding protein 1 (SREBP1c). Furthermore, 2',6'-O-acetylsalicortin (1) suppressed mRNA expression levels of C/EBPβ during the early stage of adipocyte differentiation and stearoyl coenzyme A desaturase 1 (SCD-1), acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) expression, target genes of SREBP1c. In the present study, we demonstrate that the anti-adipogenesis mechanism of 2',6'-O-acetylsalicortin (1) may be mediated via down-regulation of C/EBPα and SREBP1c dependent pathways. Through their anti-adipogenic activity, salicortin derivatives may be potential novel therapeutic agents against obesity.

  16. An enzymatically fortified ginseng extract inhibits proliferation and induces apoptosis of KATO3 human gastric cancer cells via modulation of Bax, mTOR, PKB and IκBα.

    PubMed

    Hwang, Jeong-Won; Baek, Young-Mi; Jang, Ik-Soon; Yang, Kyeong Eun; Lee, Dong-Gi; Yoon, So-Jung; Rho, Jaerang; Cho, Chong-Kwan; Lee, Yeon-Weol; Kwon, Ki-Rok; Yoo, Hwa-Seung; Sung, Jung-Suk; Kim, Shin; Park, Jong-Wook; Jang, Byeong-Churl; Choi, Jong-Soon

    2015-01-01

    Accumulative evidence suggests ginseng extract and/or its major components, ginsenosides and compound K, a metabolized ginseng saponin, have anti-cancer effects. In the present study, the effects of a ginseng butanolic extract (GBX) and an enzymatically fortified ginseng extract (FGX), with enriched ginsenosides and compound K, on the growth of KATO3 human gastric cancer cells were investigated using a cell viability assay. While treatment with GBX at 31.25-125 mg/ml for 24 h did not affect the proliferation of KATO3 cells, FGX under the same conditions inhibited cell proliferation in a concentration-dependent manner. Furthermore, Annexin V/PI-staining and flow cytometric analysis demonstrated that the population of apoptotic KATO3 cells was increased following treatment with FGX, which was greater than in the GBX-treated cells, suggesting that FGX had a stronger apoptotic effect than GBX. To investigate the underlying mechanism of the cytostatic and cytotoxic effects of the ginseng extracts, apoptosis-associated proteins were assessed using western blot analysis. The data revealed higher expression levels of B-cell lymphoma 2-associated X protein (Bax), lower expression of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor α (IκBα) and reduced phosphorylation of mammalian target of rapamycin (mTOR) and protein kinase B (PKB) in the FGX-treated KATO3 cells than in the GBX-treated cells. Collectively, these results demonstrated for the first time, to the best of our knowledge, that FGX had stronger anti-proliferative and pro-apoptotic effects on KATO3 cells than GBX. The anti-proliferative and/or pro-apoptotic effects of FGX appeared to be mediated via the upregulation of Bax, IκBα proteolysis (activation of nuclear factor-κB) and the blocking of mTOR and PKB signals. PMID:25333578

  17. Inhibition of p38 MAPK during cellular activation modulate gene expression of head kidney leukocytes isolated from Atlantic salmon (Salmo salar) fed soy bean oil or fish oil based diets.

    PubMed

    Holen, E; Winterthun, S; Du, Z-Y; Krøvel, A V

    2011-01-01

    Head kidney leukocytes isolated from Atlantic salmon fed either a diet based on fish oil (FO) or soy bean oil (VO) were used in order to evaluate if different lipid sources could contribute to cellular activation of the salmon innate immune system. A specific inhibitor of p38 MAPK, SB202190, was used to investigate the effect of lipopolysaccharide (LPS) signalling in the head kidney leukocytes. The results show that LPS up regulate IL-1β, TNF-α, Cox2 expression in leukocytes isolated from fish fed either diet. The p38 MAPK inhibitor, SB202190, reduced the LPS induced expression of these genes in both dietary groups. In LPS stimulated leukocytes isolated from VO fed fish, SB202190 showed a clear dose dependent inhibitory effect on IL-1β, TNF-α and Cox2 expression. This effect was also observed for Cox2 in leukocytes isolated from FO fed fish. Furthermore, there was a stronger mean induction of Cox2 in LPS stimulated leucocytes isolated from the VO-group compared to LPS stimulated leukocytes isolated from the FO-group. In both dietary groups, LPS stimulation of salmon head kidney leukocytes increased the induction of CD83, a dendrite cell marker, while the inhibitor reduced CD83 expression in the VO fed fish only. The inhibitor also clearly reduced hsp27 expression in VO fed fish. Indicating a p38 MAPK feedback loop, LPS significantly inhibited the expression of p38MAPK itself in both diets, while SB202190 increased p38MAPK expression especially in the VO diet group. hsp70 expression was not affected by any treatment or feed composition. There were also differences in p38MAPK protein phosphorylation comparing treatment groups but no obvious difference comparing the two dietary groups. The results indicate that dietary fatty acids have the ability to modify signalling through p38 MAPK which may have consequences for the fish's ability to handle infections and stress. Signalling through p38MAPK is ligand dependent and affects gene and protein expression differently.

  18. Supported PV module assembly

    DOEpatents

    Mascolo, Gianluigi; Taggart, David F.; Botkin, Jonathan D.; Edgett, Christopher S.

    2013-10-15

    A supported PV assembly may include a PV module comprising a PV panel and PV module supports including module supports having a support surface supporting the module, a module registration member engaging the PV module to properly position the PV module on the module support, and a mounting element. In some embodiments the PV module registration members engage only the external surfaces of the PV modules at the corners. In some embodiments the assembly includes a wind deflector with ballast secured to a least one of the PV module supports and the wind deflector. An array of the assemblies can be secured to one another at their corners to prevent horizontal separation of the adjacent corners while permitting the PV modules to flex relative to one another so to permit the array of PV modules to follow a contour of the support surface.

  19. Allosteric modulation of glycine receptors

    PubMed Central

    Yevenes, Gonzalo E; Zeilhofer, Hanns Ulrich

    2011-01-01

    Inhibitory (or strychnine sensitive) glycine receptors (GlyRs) are anion-selective transmitter-gated ion channels of the cys-loop superfamily, which includes among others also the inhibitory γ-aminobutyric acid receptors (GABAA receptors). While GABA mediates fast inhibitory neurotransmission throughout the CNS, the action of glycine as a fast inhibitory neurotransmitter is more restricted. This probably explains why GABAA receptors constitute a group of extremely successful drug targets in the treatment of a wide variety of CNS diseases, including anxiety, sleep disorders and epilepsy, while drugs specifically targeting GlyRs are virtually lacking. However, the spatially more restricted distribution of glycinergic inhibition may be advantageous in situations when a more localized enhancement of inhibition is sought. Inhibitory GlyRs are particularly relevant for the control of excitability in the mammalian spinal cord, brain stem and a few selected brain areas, such as the cerebellum and the retina. At these sites, GlyRs regulate important physiological functions, including respiratory rhythms, motor control, muscle tone and sensory as well as pain processing. In the hippocampus, RNA-edited high affinity extrasynaptic GlyRs may contribute to the pathology of temporal lobe epilepsy. Although specific modulators have not yet been identified, GlyRs still possess sites for allosteric modulation by a number of structurally diverse molecules, including alcohols, neurosteroids, cannabinoids, tropeines, general anaesthetics, certain neurotransmitters and cations. This review summarizes the present knowledge about this modulation and the molecular bases of the interactions involved. PMID:21557733

  20. Pancreatic polypepetide inhibits pancreatic enzyme secretion via a cholinergic pathway

    SciTech Connect

    Jung, G.; Louie, D.S.; Owyang, C. )

    1987-11-01

    In rat pancreatic slices, rat pancreatic polypeptide (PP) or C-terminal hexapeptide of PP (PP-(31-36)) inhibited potassium-stimulated amylase release in a dose-dependent manner. The inhibition was unaffected by addition of hexamethonium but blocked by atropine. In contrast, PP-(31-36) did not have any effect on acetylcholine- or cholecystokinin octapeptide-stimulated amylase release. In addition, when pancreatic slices were incubated with ({sup 3}H)choline, PP-(31-36) inhibited the potassium-evoked release of synthesized ({sup 3}H)acetylcholine in a dose-dependent manner. The inhibitory action of PP was unaffected by adrenergic, dopaminergic, or opioid receptor antagonists. Thus PP inhibits pancreatic enzyme secretion via presynaptic modulation of acetylcholine release. This newly identified pathway provides a novel mechanism for hormonal inhibition of pancreatic enzyme secretion via modulation of the classic neurotransmitter function.

  1. Gestalt factors modulate basic spatial vision.

    PubMed

    Sayim, B; Westheimer, G; Herzog, M H

    2010-05-01

    Human perception of a stimulus varies depending on the context in which the stimulus is presented. Such contextual modulation has often been explained by two basic neural mechanisms: lateral inhibition and spatial pooling. In the present study, we presented observers with a vernier stimulus flanked by single lines; observers' ability to discriminate the offset direction of the vernier stimulus deteriorated in accordance with both explanations. However, when the flanking lines were part of a geometric shape (i.e., a good Gestalt), this deterioration strongly diminished. These findings cannot be explained by lateral inhibition or spatial pooling. It seems that Gestalt factors play an important role in contextual modulation. We propose that contextual modulation can be used as a quantitative measure to investigate the rules governing the grouping of elements into meaningful wholes.

  2. Lunar Module Ascent Stage

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The Lunar Module 'Spider' ascent stage is photographed from the Command/Service Module on the fifth day of the Apollo 9 earth-orbital mission. The Lunar Module's descent stage had already been jettisoned.

  3. Corrosion inhibiting organic coatings

    SciTech Connect

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  4. Attention modulates visual size adaptation.

    PubMed

    Kreutzer, Sylvia; Fink, Gereon R; Weidner, Ralph

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

  5. AMPA receptor inhibition by synaptically released zinc.

    PubMed

    Kalappa, Bopanna I; Anderson, Charles T; Goldberg, Jacob M; Lippard, Stephen J; Tzounopoulos, Thanos

    2015-12-22

    The vast amount of fast excitatory neurotransmission in the mammalian central nervous system is mediated by AMPA-subtype glutamate receptors (AMPARs). As a result, AMPAR-mediated synaptic transmission is implicated in nearly all aspects of brain development, function, and plasticity. Despite the central role of AMPARs in neurobiology, the fine-tuning of synaptic AMPA responses by endogenous modulators remains poorly understood. Here we provide evidence that endogenous zinc, released by single presynaptic action potentials, inhibits synaptic AMPA currents in the dorsal cochlear nucleus (DCN) and hippocampus. Exposure to loud sound reduces presynaptic zinc levels in the DCN and abolishes zinc inhibition, implicating zinc in experience-dependent AMPAR synaptic plasticity. Our results establish zinc as an activity-dependent, endogenous modulator of AMPARs that tunes fast excitatory neurotransmission and plasticity in glutamatergic synapses.

  6. AMPA receptor inhibition by synaptically released zinc

    PubMed Central

    Kalappa, Bopanna I.; Anderson, Charles T.; Lippard, Stephen J.; Tzounopoulos, Thanos

    2015-01-01

    The vast amount of fast excitatory neurotransmission in the mammalian central nervous system is mediated by AMPA-subtype glutamate receptors (AMPARs). As a result, AMPAR-mediated synaptic transmission is implicated in nearly all aspects of brain development, function, and plasticity. Despite the central role of AMPARs in neurobiology, the fine-tuning of synaptic AMPA responses by endogenous modulators remains poorly understood. Here we provide evidence that endogenous zinc, released by single presynaptic action potentials, inhibits synaptic AMPA currents in the dorsal cochlear nucleus (DCN) and hippocampus. Exposure to loud sound reduces presynaptic zinc levels in the DCN and abolishes zinc inhibition, implicating zinc in experience-dependent AMPAR synaptic plasticity. Our results establish zinc as an activity-dependent, endogenous modulator of AMPARs that tunes fast excitatory neurotransmission and plasticity in glutamatergic synapses. PMID:26647187

  7. Ballasted photovoltaic module and module arrays

    DOEpatents

    Botkin, Jonathan; Graves, Simon; Danning, Matt

    2011-11-29

    A photovoltaic (PV) module assembly including a PV module and a ballast tray. The PV module includes a PV device and a frame. A PV laminate is assembled to the frame, and the frame includes an arm. The ballast tray is adapted for containing ballast and is removably associated with the PV module in a ballasting state where the tray is vertically under the PV laminate and vertically over the arm to impede overt displacement of the PV module. The PV module assembly can be installed to a flat commercial rooftop, with the PV module and the ballast tray both resting upon the rooftop. In some embodiments, the ballasting state includes corresponding surfaces of the arm and the tray being spaced from one another under normal (low or no wind) conditions, such that the frame is not continuously subjected to a weight of the tray.

  8. Module flammability research

    NASA Technical Reports Server (NTRS)

    Sugimura, R. S.; Otth, D. H.

    1985-01-01

    New materials were developed which show promise of fabricating modules that can pass the Underwriter Laboratories Class A burning brand test for fire ratable solar cell modules. It is concluded that fire resistant module design require special high temperature materials and constructions to achieve Class B and Class A ratings. Also, synergisms exist between back surface materials and module configuration.

  9. Module utilization committee

    NASA Technical Reports Server (NTRS)

    Volkmer, K.; Praver, G.

    1984-01-01

    Photovoltaic collector modules were declared surplus to the needs of the U.S. Dept. of Energy. The Module Utilization Committee was formed to make appropriate disposition of the surplus modules on a national basis and to act as a broker for requests for these modules originating outside of the National Photovoltaics Program.

  10. Redox modulation and human bile duct cancer inhibition by curcumin.

    PubMed

    Suphim, Bunliang; Prawan, Auemduan; Kukongviriyapan, Upa; Kongpetch, Sarinya; Buranrat, Benjaporn; Kukongviriyapan, Veerapol

    2010-01-01

    Curcumin, a major component from tumeric and well-known dietary spice, possesses various pharmacological effects. The cancer chemoprevention effect is suggested to act through its pro-oxidant property. The study was to clarify effects of curcumin on cholangiocarcinoma cells, a cancer of the bile duct that refractory to chemotherapeutic drugs. We examined time-course of oxidant formation in relation to antitumor and the adaptive antioxidant response of the cells. Curcumin induced antiproliferation and apoptosis in KKU-M214 CCA cells with concentration- and time- dependent manners. The antiproliferative effect of curcumin was observed at concentrations as low as 3 microM and was not necessarily associated with oxidative stress, while induction of apoptosis required significant production of superoxide anion, suppression of cellular redox and collapse of mitochondrial transmembrane potential. Western blot analysis showed a temporal relationship between the suppression of nuclear NF-kappaB with Bcl-XL protein levels. Up-regulation of p53 and Bax was associated with marked oxidative stress and apoptosis. Curcumin also induced Nrf2 protein expression with up-regulation of gamma-glutamylcysteine ligase mRNA and increased cellular antioxidant, glutathione. The study suggests that curcumin could be developed into an effective chemoprevention against CCA.

  11. Intrarenal dopamine inhibits progression of diabetic nephropathy.

    PubMed

    Zhang, Ming-Zhi; Yao, Bing; Yang, Shilin; Yang, Haichun; Wang, Suwan; Fan, Xiaofeng; Yin, Huiyong; Fogo, Agnes B; Moeckel, Gilbert W; Harris, Raymond C

    2012-10-01

    The kidney has a local intrarenal dopaminergic system, and in the kidney, dopamine modulates renal hemodynamics, inhibits salt and fluid reabsorption, antagonizes the renin-angiotensin system, and inhibits oxidative stress. The current study examined the effects of alterations in the intrarenal dopaminergic system on kidney structure and function in models of type 1 diabetes. We studied catechol-O-methyl-transferase (COMT)(-/-) mice, which have increased renal dopamine production due to decreased dopamine metabolism, and renal transplantation was used to determine whether the effects seen with COMT deficiency were kidney-specific. To determine the effects of selective inhibition of intrarenal dopamine production, we used mice with proximal tubule deletion of aromatic amino acid decarboxylase (ptAADC(-/-)). Compared with wild-type diabetic mice, COMT(-/-) mice had decreased hyperfiltration, decreased macula densa cyclooxygenase-2 expression, decreased albuminuria, decreased glomerulopathy, and inhibition of expression of markers of inflammation, oxidative stress, and fibrosis. These differences were also seen in diabetic mice with a transplanted kidney from COMT(-/-) mice. In contrast, diabetic ptAADC(-/-) mice had increased nephropathy. Our study demonstrates an important role of the intrarenal dopaminergic system to modulate the development and progression of diabetic kidney injury and indicate that the decreased renal dopamine production may have important consequences in the underlying pathogenesis of diabetic nephropathy. PMID:22688335

  12. Modulational effects in accelerators

    SciTech Connect

    Satogata, T.

    1997-12-01

    We discuss effects of field modulations in accelerators, specifically those that can be used for operational beam diagnostics and beam halo control. In transverse beam dynamics, combined effects of nonlinear resonances and tune modulations influence diffusion rates with applied tune modulation has been demonstrated. In the longitudinal domain, applied RF phase and voltage modulations provide mechanisms for parasitic halo transport, useful in slow crystal extraction. Experimental experiences with transverse tune and RF modulations are also discussed.

  13. Almond brush module cutter

    SciTech Connect

    Zohns, M.A.; Jenkins, B.M.; Mehlschau, J.J.; Morrison, D.

    1983-06-01

    This paper addresses the design, construction, and evaluation of an almond brush module cutter. The module cutter is one link in a system which processes tree prunings for fuel and fiber. This system includes a modified cotton module builder, a module mover, the cutter, and a tub grinder. An economic analysis of the cutter is presented along with the problems involved in cutting brush modules.

  14. Synaptic inhibition and disinhibition in the spinal dorsal horn.

    PubMed

    Prescott, Steven A

    2015-01-01

    Nociceptive signals originating in the periphery must be transmitted to the brain to evoke pain. Rather than being conveyed unchanged, those signals undergo extensive processing in the spinal dorsal horn. Synaptic inhibition plays a crucial role in that processing. On the one hand, neuropathy and inflammation are associated with reduced spinal inhibition; on the other hand, the hypersensitivity associated with inflammatory and neuropathic pain can be reproduced by blocking inhibition at the spinal level. To understand the consequences of disinhibition and how to therapeutically reverse it, one must understand how synaptic inhibition normally operates. To that end, this chapter will discuss the structure and function of GABAA and glycine receptors together with the role of associated molecules involved in transmitter handling and chloride regulation. Mechanisms by which inhibition modulates cellular excitability will be described. The chapter will end with discussion of how inhibition goes awry under pathological conditions and what the implications are for the treatment of resulting pain. PMID:25744679

  15. Saccadic Inhibition in Reading

    ERIC Educational Resources Information Center

    Reingold, Eyal M.; Stampe, Dave M.

    2004-01-01

    In 5 experiments, participants read text that was briefly replaced by a transient image for 33 ms at random intervals. A decrease in saccadic frequency, referred to as saccadic inhibition, occurred as early as 60-70 ms following the onset of abrupt changes in visual input. It was demonstrated that the saccadic inhibition was influenced by the…

  16. Commerical module test program

    NASA Technical Reports Server (NTRS)

    Smokier, M. I.

    1986-01-01

    The results are presented for a program of qualification testing of commercial crystalline silicon modules from nine manufacturers in five countries. The outcome demonstrated the effective role of the Block 5 Qualification Tests in the development of reliable modules.

  17. Integrated spatial light modulator

    NASA Astrophysics Data System (ADS)

    Yu, Dong X.; Storti, George M.; Wrigley, Charles Y.

    1992-08-01

    We described here an integrated spatial light modulator (SLM) employing Quantex electron trapping (ET) materials. The light modulation is accomplished by emission of ET material, upon incident coherent infrared light, where a pattern is written to by previous visible light excitation. The ET based spatial light modulators offer unique advantages over other SLM devices, such as capability of converting incoherent input to coherent light output and of integrating the modulator, the photodetector, and the memory into a single, rugged unit.

  18. Specific regulation of male rat liver cytosolic estrogen receptor by the modulator of the glucocorticoid receptor.

    PubMed

    Celiker, M Y; Haas, A; Saunders, D; Litwack, G

    1993-08-31

    Modulator is a novel low-molecular-weight organic compound that regulates activities of glucocorticoid and mineralocorticoid receptors as well as protein kinase C. In this study we show that male rat liver cytosolic estrogen receptor activation is inhibited by modulator in a dose-dependent manner. Fifty percent inhibition is obtained with 1 unit/ml modulator purified from bovine liver which is within the physiological concentration for modulator. However, sheep uterine cytosolic estrogen and androgen receptors are insensitive to regulation by modulator. Exogenous sodium molybdate treatment inhibits activation of all of these receptors of liver or uterus origin in an identical manner, further differentiating the effects of modulator and the molybdate anion. PMID:8363596

  19. Frequency modulated oscillator

    NASA Technical Reports Server (NTRS)

    Honnell, M. A. (Inventor)

    1977-01-01

    A frequency modulated push-pull oscillator in which the non-linear characteristic of varactors producing frequency modulation is compensated for by an opposite non-linear characteristic of a field effect transistor providing modulating bias to the varactors is described.

  20. Modulating lignin in plants

    SciTech Connect

    Apuya, Nestor; Bobzin, Steven Craig; Okamuro, Jack; Zhang, Ke

    2013-01-29

    Materials and methods for modulating (e.g., increasing or decreasing) lignin content in plants are disclosed. For example, nucleic acids encoding lignin-modulating polypeptides are disclosed as well as methods for using such nucleic acids to generate transgenic plants having a modulated lignin content.

  1. Rescue Manual. Module 5.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Instructional Materials Lab.

    This learner manual for rescuers covers the current techniques or practices required in the rescue service. The fifth of 10 modules contains information on hazardous materials. Key points, an introduction, and conclusion accompany substantive material in this module. In addition, the module contains a Department of Transportation guide chart on…

  2. Integrating Module - NEMS Documentation

    EIA Publications

    2014-01-01

    Provides an overview of the complete National Energy Modeling System (NEMS) model, and includes brief descriptions of the modules with which the Integrating Module interacts. The emphasis and focus, however, is on the structure and function of the Integrating Module of NEMS.

  3. Ormeloxifene efficiently inhibits ovarian cancer growth

    PubMed Central

    Maher, Diane M.; Khan, Sheema; Nordquist, Jordan; Ebeling, Mara C.; Bauer, Nichole A.; Kopel, Lucas; Singh, Man Mohan; Halaweish, Fathi; Bell, Maria C.; Jaggi, Meena; Chauhan, Subhash C.

    2014-01-01

    Ovarian cancer continues to be a leading cause of cancer related deaths for women. Anticancer agents effective against chemo-resistant cells are greatly needed for ovarian cancer treatment. Repurposing drugs currently in human use is an attractive strategy for developing novel cancer treatments with expedited translation into clinical trials. Therefore, we examined whether ormeloxifene (ORM), a non-steroidal Selective Estrogen Receptor Modulator (SERM) currently used for contraception, is therapeutically effective at inhibiting ovarian cancer growth. We report that ORM treatment inhibits cell growth and induces apoptosis in ovarian cancer cell lines, including cell lines resistant to cisplatin. Furthermore, ORM treatment decreases Akt phosphorylation, increases p53 phosphorylation, and modulates the expression and localization patterns of p27, cyclin E, cyclin D1, and CDK2. In a pre-clinical xenograft mouse ORM treatment significantly reduces tumorigenesis and metastasis. These results indicate that ORM effectively inhibits the growth of cisplatin resistant ovarian cancer cells. ORM is currently in human use and has an established record of patient safety. Our encouraging in vitro and pre-clinical in vivo findings indicate that ORM is a promising candidate for the treatment of ovarian cancer. PMID:25306892

  4. Inhibition of selectin binding

    DOEpatents

    Nagy, Jon O.; Spevak, Wayne R.; Dasgupta, Falguni; Bertozzi, Caroline

    1999-01-01

    This invention provides compositions for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 10.sup.6 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, these composition scan be used to palliate certain inflammatory and immunological conditions.

  5. Inhibition of selectin binding

    DOEpatents

    Nagy, Jon O.; Spevak, Wayne R.; Dasgupta, Falguni; Bertozzi, Caroline

    2001-10-09

    This invention provides compositions for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 10.sup.6 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, these composition scan be used to palliate certain inflammatory and immunological conditions.

  6. Inhibition of selectin binding

    DOEpatents

    Nagy, Jon O.; Spevak, Wayne R.; Dasgupta, Falguni; Bertozzi, Carolyn

    1999-10-05

    This invention provides a system for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 10.sup.6 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, this system can be used to palliate certain inflammatory and immunological conditions.

  7. Spatial Light Amplifier Modulators

    NASA Technical Reports Server (NTRS)

    Eng, Sverre T.; Olsson, N. Anders

    1992-01-01

    Spatial light amplifier modulators (SLAM's) are conceptual devices that effect two-dimensional spatial modulation in optical computing and communication systems. Unlike current spatial light modulators, these provide gain. Optical processors incorporating SLAM's designed to operate in reflection or transmission mode. Each element of planar SLAM array is optical amplifier - surface-emitting diode laser. Array addressed electrically with ac modulating signals superimposed on dc bias currents supplied to lasers. SLAM device provides both desired modulation and enough optical gain to enable splitting of output signal into many optical fibers without excessive loss of power.

  8. AOP description: Acetylcholinesterase inhibition

    EPA Science Inventory

    This adverse outcome pathway (AOP) leverages existing knowledge in the open literature to describe the linkage between inhibition of acetylcholinesterase (AChE) and the subsequent mortality resulting from impacts at cholinergic receptors. The AOP takes a chemical category approa...

  9. Microglia modulate respiratory rhythm generation and autoresuscitation.

    PubMed

    Lorea-Hernández, Jonathan-Julio; Morales, Teresa; Rivera-Angulo, Ana-Julia; Alcantara-Gonzalez, David; Peña-Ortega, Fernando

    2016-04-01

    Inflammation has been linked to the induction of apneas and Sudden Infant Death Syndrome, whereas proinflammatory mediators inhibit breathing when applied peripherally or directly into the CNS. Considering that peripheral inflammation can activate microglia in the CNS and that this cell type can directly release all proinflammatory mediators that modulate breathing, it is likely that microglia can modulate breathing generation. It might do so also in hypoxia, since microglia are sensitive to hypoxia, and peripheral proinflammatory conditions affect gasping generation and autoresuscitation. Here, we tested whether microglial activation or inhibition affected respiratory rhythm generation. By measuring breathing as well as the activity of the respiratory rhythm generator (the preBötzinger complex), we found that several microglial activators or inhibitors, applied intracisternally in vivo or in the recording bath in vitro, affect the generation of the respiratory rhythms both in normoxia and hypoxia. Furthermore, microglial activation with lipopolysaccharide affected the ability of the animals to autoresuscitate after hypoxic conditions, an effect that is blocked when lipopolysaccharide is co-applied with the microglial inhibitor minocycline. Moreover, we found that the modulation of respiratory rhythm generation induced in vitro by microglial inhibitors was reproduced by microglial depletion. In conclusion, our data show that microglia can modulate respiratory rhythm generation and autoresuscitation.

  10. Method for inhibiting corrosion

    SciTech Connect

    Wu, Y.; Stapp, P. R.

    1985-12-03

    A composition comprising the reaction adduct or neutralized product resulting from the reaction of a maleic anhydride and an oil containing a polynuclear aromatic compound is provided which, when applied to a metal surface, forms a corrosion-inhibiting film thereon. The composition is particularly useful in the treatment of down-hole metal surfaces in oil and gas wells to inhibit the corrosion of the metal.

  11. Saw palmetto ethanol extract inhibits adipocyte differentiation.

    PubMed

    Villaverde, Nicole; Galvis, Adriana; Marcano, Adriana; Priestap, Horacio A; Bennett, Bradley C; Barbieri, M Alejandro

    2013-07-01

    The fruits of saw palmetto have been used for the treatment of a variety of urinary and reproductive system problems. In this study we investigated whether the fruit extracts affect in vitro adipogenesis. Saw palmetto ethanol extract inhibited the lipid droplet accumulation by induction media in a dose-dependent manner, and it also attenuated the protein expressions of C-EBPα and PPARγ. Phosphorylation of Erk1/2 and Akt1 were also decreased by saw palmetto ethanol extract. This report suggests that saw palmetto extracts selectively affect the adipocyte differentiation through the modulation of several key factors that play a critical role during adipogenesis.

  12. Cerebellar cortical inhibition and classical eyeblink conditioning.

    PubMed

    Bao, Shaowen; Chen, Lu; Kim, Jeansok J; Thompson, Richard F

    2002-02-01

    The cerebellum is considered a brain structure in which memories for learned motor responses (e.g., conditioned eyeblink responses) are stored. Within the cerebellum, however, the relative importance of the cortex and the deep nuclei in motor learning/memory is not entirely clear. In this study, we show that the cerebellar cortex exerts both basal and stimulus-activated inhibition to the deep nuclei. Sequential application of a gamma-aminobutyric acid type A receptor (GABA(A)R) agonist and a noncompetitive GABA(A)R antagonist allows selective blockade of stimulus-activated inhibition. By using the same sequential agonist and antagonist methods in behaving animals, we demonstrate that the conditioned response (CR) expression and timing are completely dissociable and involve different inhibitory inputs; although the basal inhibition modulates CR expression, the conditioned stimulus-activated inhibition is required for the proper timing of the CR. In addition, complete blockade of cerebellar deep nuclear GABA(A)Rs prevents CR acquisition. Together, these results suggest that different aspects of the memories for eyeblink CRs are encoded in the cerebellar cortex and the cerebellar deep nuclei.

  13. Loadable Hypervisor Modules

    SciTech Connect

    Naughton, III, Thomas J; Vallee, Geoffroy R; Scott, Stephen L; Aderholdt, Ferrol

    2010-01-01

    This paper discusses the implementation of a new hypervisor mechanism for loading dynamic shared objects (modules) at runtime. These loadable hypervisor modules (LHM) are modeled after the loadable kernel modules used in Linux. We detail the current LHM implementation based on the Xen hypervisor. Potential use cases for this LHM mechanism include dynamic hypervisor instrumentation for debug tracing or performance analysis. We discuss the initial LHM prototype and future plans.

  14. Cavity enhanced terahertz modulation

    SciTech Connect

    Born, N.; Scheller, M.; Moloney, J. V.; Koch, M.

    2014-03-10

    We present a versatile concept for all optical terahertz (THz) amplitude modulators based on a Fabry-Pérot semiconductor cavity design. Employing the high reflectivity of two parallel meta-surfaces allows for trapping selected THz photons within the cavity and thus only a weak optical modulation of the semiconductor absorbance is required to significantly damp the field within the cavity. The optical switching yields to modulation depths of more than 90% with insertion efficiencies of 80%.

  15. Modulation of Aromatase by Phytoestrogens

    PubMed Central

    Lephart, Edwin D.

    2015-01-01

    The aromatase enzyme catalyzes the conversion of androgens to estrogens in many human tissues. Estrogens are known to stimulate cellular proliferation associated with certain cancers and protect against adverse symptoms during the peri- and postmenopausal intervals. Phytoestrogens are a group of plant derived naturally occurring compounds that have chemical structures similar to estrogen. Since phytoestrogens are known to be constituents of animal/human food sources, these compounds have received increased research attention. Phytoestrogens may contribute to decreased cancer risk by the inhibition of aromatase enzyme activity and CYP19 gene expression in human tissues. This review covers (a) the aromatase enzyme (historical descriptions on function, activity, and gene characteristics), (b) phytoestrogens in their classifications and applications to human health, and (c) a chronological coverage of aromatase activity modulated by phytoestrogens from the early 1980s to 2015. In general, phytoestrogens act as aromatase inhibitors by (a) decreasing aromatase gene expression, (b) inhibiting the aromatase enzyme itself, or (c) in some cases acting at both levels of regulation. The findings presented herein are consistent with estrogen's impact on health and phytoestrogen's potential as anticancer treatments, but well-controlled, large-scale studies are warranted to determine the effectiveness of phytoestrogens on breast cancer and age-related diseases. PMID:26798508

  16. FASTBUS Snoop Diagnostic Module

    SciTech Connect

    Walz, H.V.; Downing, R.

    1980-11-01

    Development of the FASTBUS Snoop Module, undertaken as part of the prototype program for the new interlaboratory data bus standard, is described. The Snoop Module resides on a FASTBUS crate segment and provides diagnostic monitoring and testing capability. Communication with a remote host computer is handled independent of FASTBUS through a serial link. The module consists of a high-speed ECL front-end to monitor and single-step FASTBUS cycles, a master-slave interface, and a control microprocessor with serial communication ports. Design details and performance specifications of the prototype module are reported. 9 figures, 1 table.

  17. Bubble memory module

    NASA Technical Reports Server (NTRS)

    Bohning, O. D.; Becker, F. J.

    1980-01-01

    Design, fabrication and test of partially populated prototype recorder using 100 kilobit serial chips is described. Electrical interface, operating modes, and mechanical design of several module configurations are discussed. Fabrication and test of the module demonstrated the practicality of multiplexing resulting in lower power, weight, and volume. This effort resulted in the completion of a module consisting of a fully engineered printed circuit storage board populated with 5 of 8 possible cells and a wire wrapped electronics board. Interface of the module is 16 bits parallel at a maximum of 1.33 megabits per second data rate on either of two interface buses.

  18. Bracket for photovoltaic modules

    SciTech Connect

    Ciasulli, John; Jones, Jason

    2014-06-24

    Brackets for photovoltaic ("PV") modules are described. In one embodiment, a saddle bracket has a mounting surface to support one or more PV modules over a tube, a gusset coupled to the mounting surface, and a mounting feature coupled to the gusset to couple to the tube. The gusset can have a first leg and a second leg extending at an angle relative to the mounting surface. Saddle brackets can be coupled to a torque tube at predetermined locations. PV modules can be coupled to the saddle brackets. The mounting feature can be coupled to the first gusset and configured to stand the one or more PV modules off the tube.

  19. Silicon photonic heater-modulator

    DOEpatents

    Zortman, William A.; Trotter, Douglas Chandler; Watts, Michael R.

    2015-07-14

    Photonic modulators, methods of forming photonic modulators and methods of modulating an input optical signal are provided. A photonic modulator includes a disk resonator having a central axis extending along a thickness direction of the disk resonator. The disk resonator includes a modulator portion and a heater portion. The modulator portion extends in an arc around the central axis. A PN junction of the modulator portion is substantially normal to the central axis.

  20. Zinc Inhibits Hedgehog Autoprocessing

    PubMed Central

    Xie, Jian; Owen, Timothy; Xia, Ke; Singh, Ajay Vikram; Tou, Emiley; Li, Lingyun; Arduini, Brigitte; Li, Hongmin; Wan, Leo Q.; Callahan, Brian; Wang, Chunyu

    2015-01-01

    Zinc is an essential trace element with wide-ranging biological functions, whereas the Hedgehog (Hh) signaling pathway plays crucial roles in both development and disease. Here we show that there is a mechanistic link between zinc and Hh signaling. The upstream activator of Hh signaling, the Hh ligand, originates from Hh autoprocessing, which converts the Hh precursor protein to the Hh ligand. In an in vitro Hh autoprocessing assay we show that zinc inhibits Hh autoprocessing with a Ki of 2 μm. We then demonstrate that zinc inhibits Hh autoprocessing in a cellular environment with experiments in primary rat astrocyte culture. Solution NMR reveals that zinc binds the active site residues of the Hh autoprocessing domain to inhibit autoprocessing, and isothermal titration calorimetry provided the thermodynamics of the binding. In normal physiology, zinc likely acts as a negative regulator of Hh autoprocessing and inhibits the generation of Hh ligand and Hh signaling. In many diseases, zinc deficiency and elevated level of Hh ligand co-exist, including prostate cancer, lung cancer, ovarian cancer, and autism. Our data suggest a causal relationship between zinc deficiency and the overproduction of Hh ligand. PMID:25787080

  1. Nitric oxide inhibition strategies

    PubMed Central

    Wong, Vivian (Wai Chong); Lerner, Ethan

    2015-01-01

    Nitric oxide is involved in many physiologic processes. There are efforts, described elsewhere in this volume, to deliver nitric oxide to tissues as a therapy. Nitric oxide also contributes to pathophysiologic processes. Inhibiting nitric oxide or its production can thus also be of therapeutic benefit. This article addresses such inhibitory strategies. PMID:26634146

  2. Membrane module assembly

    DOEpatents

    Kaschemekat, Jurgen

    1994-01-01

    A membrane module assembly adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation.

  3. Cosmetology. Computerized Learning Modules.

    ERIC Educational Resources Information Center

    Finnerty, Kathy, Ed.

    Intended to help reading-limited students meet course objectives, these 11 modules are based on instructional materials in cosmetology that have a higher readability equivalent. Modules cover bacteriology, chemical waving, scalp and hair massage, chemistry, hair shaping, hairstyling, chemical hair relaxing, hair coloring, skin and scalp,…

  4. Logs Perl Module

    2007-04-04

    A perl module designed to read and parse the voluminous set of event or accounting log files produced by a Portable Batch System (PBS) server. This module can filter on date-time and/or record type. The data can be returned in a variety of formats.

  5. Module Safety Issues (Presentation)

    SciTech Connect

    Wohlgemuth, J.

    2012-02-01

    Description of how to make PV modules so that they are less likely to turn into safety hazards. Making modules inherently safer with minimum additional cost is the preferred approach for PV. Safety starts with module design to ensure redundancy within the electrical circuitry to minimize open circuits and proper mounting instructions to prevent installation related ground faults. Module manufacturers must control the raw materials and processes to ensure that that every module is built like those qualified through the safety tests. This is the reason behind the QA task force effort to develop a 'Guideline for PV Module Manufacturing QA'. Periodic accelerated stress testing of production products is critical to validate the safety of the product. Combining safer PV modules with better systems designs is the ultimate goal. This should be especially true for PV arrays on buildings. Use of lower voltage dc circuits - AC modules, DC-DC converters. Use of arc detectors and interrupters to detect arcs and open the circuits to extinguish the arcs.

  6. Lunar Module Communications

    NASA Technical Reports Server (NTRS)

    Interbartolo, Michael A.

    2009-01-01

    This slide presentation reviews the Apollo lunar module communications. It describes several changes in terminology from the Apollo era to more recent terms. It reviews: (1) Lunar Module Antennas and Functions (2). Earth Line of Sight Communications Links (3) No Earth Line of Sight Communications Links (4) Lunar Surface Communications Links (5) Signal-Processing Assembly (6) Instrumentation System (7) Some Communications Problems Encountered

  7. Membrane module assembly

    DOEpatents

    Kaschemekat, J.

    1994-03-15

    A membrane module assembly is described which is adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation. 2 figures.

  8. Principles of Teaching. Module.

    ERIC Educational Resources Information Center

    Rhoades, Joseph W.

    This module on principles of teaching is 1 in a series of 10 modules written for vocational education teacher education programs. It is designed to enable the teacher to do the following: (1) identify subject matter and integrate that subject matter with thought-provoking questions; (2) organize and demonstrate good questioning techniques; and (3)…

  9. Human Development Student Modules.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This set of 61 student learning modules deals with various topics pertaining to human development. The modules, which are designed for use in performance-based vocational education programs, each contain the following components: an introduction for the student, a performance objective, a variety of learning activities, content information, a…

  10. Touch inhibits subcortical and cortical nociceptive responses

    PubMed Central

    Mancini, Flavia; Beaumont, Anne-Lise; Hu, Li; Haggard, Patrick; Iannetti, Gian Domenico D.

    2015-01-01

    Abstract The neural mechanisms of the powerful analgesia induced by touching a painful body part are controversial. A long tradition of neurophysiologic studies in anaesthetized spinal animals indicate that touch can gate nociceptive input at spinal level. In contrast, recent studies in awake humans have suggested that supraspinal mechanisms can be sufficient to drive touch-induced analgesia. To investigate this issue, we evaluated the modulation exerted by touch on established electrophysiologic markers of nociceptive function at both subcortical and cortical levels in humans. Aδ and C skin nociceptors were selectively activated by high-power laser pulses. As markers of subcortical and cortical function, we recorded the laser blink reflex, which is generated by brainstem circuits before the arrival of nociceptive signals at the cortex, and laser-evoked potentials, which reflect neural activity of a wide array of cortical areas. If subcortical nociceptive responses are inhibited by concomitant touch, supraspinal mechanisms alone are unlikely to be sufficient to drive touch-induced analgesia. Touch induced a clear analgesic effect, suppressed the laser blink reflex, and inhibited both Aδ-fibre and C-fibre laser-evoked potentials. Thus, we conclude that touch-induced analgesia is likely to be mediated by a subcortical gating of the ascending nociceptive input, which in turn results in a modulation of cortical responses. Hence, supraspinal mechanisms alone are not sufficient to mediate touch-induced analgesia. PMID:26058037

  11. Solar energy modulator

    NASA Technical Reports Server (NTRS)

    Hale, R. R. (Inventor); Mcdougal, A. R.

    1984-01-01

    A module is described with a receiver having a solar energy acceptance opening and supported by a mounting ring along the optic axis of a parabolic mirror in coaxial alignment for receiving solar energy from the mirror, and a solar flux modulator plate for varying the quantity of solar energy flux received by the acceptance opening of the module. The modulator plate is characterized by an annular, plate-like body, the internal diameter of which is equal to or slightly greater than the diameter of the solar energy acceptance opening of the receiver. Slave cylinders are connected to the modulator plate for supporting the plate for axial displacement along the axis of the mirror, therby shading the opening with respect to solar energy flux reflected from the surface of the mirror to the solar energy acceptance opening.

  12. How many carbonic anhydrase inhibition mechanisms exist?

    PubMed

    Supuran, Claudiu T

    2016-01-01

    Six genetic families of the enzyme carbonic anhydrase (CA, EC 4.2.1.1) were described to date. Inhibition of CAs has pharmacologic applications in the field of antiglaucoma, anticonvulsant, anticancer, and anti-infective agents. New classes of CA inhibitors (CAIs) were described in the last decade with enzyme inhibition mechanisms differing considerably from the classical inhibitors of the sulfonamide or anion type. Five different CA inhibition mechanisms are known: (i) the zinc binders coordinate to the catalytically crucial Zn(II) ion from the enzyme active site, with the metal in tetrahedral or trigonal bipyramidal geometries. Sulfonamides and their isosters, most anions, dithiocarbamates and their isosters, carboxylates, and hydroxamates bind in this way; (ii) inhibitors that anchor to the zinc-coordinated water molecule/hydroxide ion (phenols, carboxylates, polyamines, 2-thioxocoumarins, sulfocoumarins); (iii) inhibitors which occlude the entrance to the active site cavity (coumarins and their isosters), this binding site coinciding with that where CA activators bind; (iv) compounds which bind out of the active site cavity (a carboxylic acid derivative was seen to inhibit CA in this manner), and (v) compounds for which the inhibition mechanism is not known, among which the secondary/tertiary sulfonamides as well as imatinib/nilotinib are the most investigated examples. As CAIs are used clinically in many pathologies, with a sulfonamide inhibitor (SLC-0111) in Phase I clinical trials for the management of metastatic solid tumors, this review updates the recent findings in the field which may be useful for a structure-based drug design approach of more selective/potent modulators of the activity of these enzymes. PMID:26619898

  13. Behavioural inhibition: is it a risk factor for anxiety?

    PubMed

    Lahat, Ayelet; Hong, Melanie; Fox, Nathan A

    2011-06-01

    Behavioural inhibition is a stable temperamental trait that is identifiable during infancy and toddlerhood and is characterized by fearful reactivity to novelty. Children identified as behaviourally inhibited have been shown to be at increased risk for developing anxiety disorders such as social phobia. The current review addresses the link between behavioural inhibition and the risk for developing anxiety disorders. Research suggests that this risk may be modulated by a number of extrinsic and intrinsic factors. Extrinsic factors include particular parental beliefs, parenting styles, and childrearing contexts. Intrinsic factors include executive function capacities such as attention bias, attention shifting, inhibitory control, and self-monitoring. In the present paper we review the contribution of these factors to the development of anxiety in behaviourally inhibited children.

  14. Behavioural inhibition: is it a risk factor for anxiety?

    PubMed

    Lahat, Ayelet; Hong, Melanie; Fox, Nathan A

    2011-06-01

    Behavioural inhibition is a stable temperamental trait that is identifiable during infancy and toddlerhood and is characterized by fearful reactivity to novelty. Children identified as behaviourally inhibited have been shown to be at increased risk for developing anxiety disorders such as social phobia. The current review addresses the link between behavioural inhibition and the risk for developing anxiety disorders. Research suggests that this risk may be modulated by a number of extrinsic and intrinsic factors. Extrinsic factors include particular parental beliefs, parenting styles, and childrearing contexts. Intrinsic factors include executive function capacities such as attention bias, attention shifting, inhibitory control, and self-monitoring. In the present paper we review the contribution of these factors to the development of anxiety in behaviourally inhibited children. PMID:21923226

  15. Deeper Insights into the Allosteric Modulation of Ionotropic Glutamate Receptors.

    PubMed

    Regan, Michael C; Furukawa, Hiro

    2016-09-21

    Two articles in this issue of Neuron (Yelshanskaya et al., 2016; Yi et al., 2016) explore the structural basis of allosteric inhibition in ionotropic glutamate receptors, providing key insights into how iGluRs function in the brain as well as how they might be pharmacologically modulated in neurological disorders and disease. PMID:27657445

  16. Photovoltaic module and interlocked stack of photovoltaic modules

    DOEpatents

    Wares, Brian S.

    2014-09-02

    One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

  17. Optical modulator system

    NASA Technical Reports Server (NTRS)

    Brand, J.

    1972-01-01

    The fabrication, test, and delivery of an optical modulator system which will operate with a mode-locked Nd:YAG laser indicating at either 1.06 or 0.53 micrometers is discussed. The delivered hardware operates at data rates up to 400 Mbps and includes a 0.53 micrometer electrooptic modulator, a 1.06 micrometer electrooptic modulator with power supply and signal processing electronics with power supply. The modulators contain solid state drivers which accept digital signals with MECL logic levels, temperature controllers to maintain a stable thermal environment for the modulator crystals, and automatic electronic compensation to maximize the extinction ratio. The modulators use two lithium tantalate crystals cascaded in a double pass configuration. The signal processing electronics include encoding electronics which are capable of digitizing analog signals between the limit of + or - 0.75 volts at a maximum rate of 80 megasamples per second with 5 bit resolution. The digital samples are serialized and made available as a 400 Mbps serial NRZ data source for the modulators. A pseudorandom (PN) generator is also included in the signal processing electronics. This data source generates PN sequences with lengths between 31 bits and 32,767 bits in a serial NRZ format at rates up to 400 Mbps.

  18. Amplitude Modulator Chassis

    SciTech Connect

    Erbert, G

    2009-09-01

    The Amplitude Modulator Chassis (AMC) is the final component in the MOR system and connects directly to the PAM input through a 100-meter fiber. The 48 AMCs temporally shape the 48 outputs of the MOR using an arbitrary waveform generator coupled to an amplitude modulator. The amplitude modulation element is a two stage, Lithium Niobate waveguide device, where the intensity of the light passing through the device is a function of the electrical drive applied. The first stage of the modulator is connected to a programmable high performance Arbitrary Waveform Generator (AWG) consisting of 140 impulse generators space 250 ps apart. An arbitrary waveform is generated by independently varying the amplitude of each impulse generator and then summing the impulses together. In addition to the AWG a short pulse generator is also connected to the first stage of the modulator to provide a sub 100-ps pulse used for timing experiments. The second stage of the modulator is connect to a square pulse generator used to further attenuate any pre or post pulse light passing through the first stage of the modulator. The fast rise and fall time of the square pulse generator is also used to produce fast rise and fall times of the AWG by clipping the AWG pulse. For maximum extinction, a pulse bias voltage is applied to each stage of the modulator. A pulse voltage is applied as opposed to a DC voltage to prevent charge buildup on the modulator. Each bias voltage is adjustable to provide a minimum of 50-dB extinction. The AMC is controlled through ICCS to generate the desired temporal pulse shape. This process involves a closed-loop control algorithm, which compares the desired temporal waveform to the produced optical pulse, and iterates the programming of the AWG until the two waveforms agree within an allowable tolerance.

  19. Autonomous cotton module forming system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton producers often have difficulty finding adequate labor during harvest. Module builder operators are often inexperienced and may build poorly shaped modules. Equipment manufacturers have recently introduced harvesters with on-board module building capabilities to reduce labor requirements; h...

  20. Substrate inhibition of transketolase.

    PubMed

    Solovjeva, Olga N; Kovina, Marina V; Kochetov, German A

    2016-03-01

    We studied the influence of the acceptor substrate of transketolase on the activity of the enzyme in the presence of reductants. Ribose-5-phosphate in the presence of cyanoborohydride decreased the transketolase catalytic activity. The inhibition is caused by the loss of catalytic function of the coenzyme-thiamine diphosphate. Similar inhibitory effect was observed in the presence of NADPH. This could indicate its possible regulatory role not only towards transketolase, but also towards the pentose phosphate pathway of carbohydrate metabolism overall, taking into account the fact that it inhibits not only transketolase but also another enzyme of the pentose phosphate pathway--glucose 6-phosphate dehydrogenase [Eggleston L.V., Krebs H.A. Regulation of the pentose phosphate cycle, Biochem. J. 138 (1974) 425-435]. PMID:26708478

  1. Water heater control module

    DOEpatents

    Hammerstrom, Donald J

    2013-11-26

    An advanced electric water heater control system that interfaces with a high temperature cut-off thermostat and an upper regulating thermostat. The system includes a control module that is electrically connected to the high-temperature cut-off thermostat and the upper regulating thermostat. The control module includes a switch to open or close the high-temperature cut-off thermostat and the upper regulating thermostat. The control module further includes circuitry configured to control said switch in response to a signal selected from the group of an autonomous signal, a communicated signal, and combinations thereof.

  2. Sonication standard laboratory module

    DOEpatents

    Beugelsdijk, Tony; Hollen, Robert M.; Erkkila, Tracy H.; Bronisz, Lawrence E.; Roybal, Jeffrey E.; Clark, Michael Leon

    1999-01-01

    A standard laboratory module for automatically producing a solution of cominants from a soil sample. A sonication tip agitates a solution containing the soil sample in a beaker while a stepper motor rotates the sample. An aspirator tube, connected to a vacuum, draws the upper layer of solution from the beaker through a filter and into another beaker. This beaker can thereafter be removed for analysis of the solution. The standard laboratory module encloses an embedded controller providing process control, status feedback information and maintenance procedures for the equipment and operations within the standard laboratory module.

  3. Optical modulator including grapene

    DOEpatents

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  4. Modulated curvaton decay

    SciTech Connect

    Assadullahi, Hooshyar; Wands, David; Firouzjahi, Hassan; Namjoo, Mohammad Hossein E-mail: firouz@mail.ipm.ir E-mail: david.wands@port.ac.uk

    2013-03-01

    We study primordial density perturbations generated by the late decay of a curvaton field whose decay rate may be modulated by the local value of another isocurvature field, analogous to models of modulated reheating at the end of inflation. We calculate the primordial density perturbation and its local-type non-Gaussianity using the sudden-decay approximation for the curvaton field, recovering standard curvaton and modulated reheating results as limiting cases. We verify the Suyama-Yamaguchi inequality between bispectrum and trispectrum parameters for the primordial density field generated by multiple field fluctuations, and find conditions for the bound to be saturated.

  5. Modulation of the extinction of fear learning.

    PubMed

    Myskiw, Jociane C; Izquierdo, Ivan; Furini, Cristiane R G

    2014-06-01

    We review recent work on extinction learning with emphasis on its modulation. Extinction is the learned inhibition of responding to previously acquired tasks. Like other forms of learning, it can be modulated by a variety of neurotransmitter systems and behavioral procedures. This bears on its use in the treatment of fear memories, particularly in posttraumatic stress disorder (PTSD), for which it is the treatment of choice, often under the name of exposure therapy. There have not been many laboratories interested in the modulation of extinction, but the available data, although not very abundant, are quite conclusive. Most studies on the nature of extinction and on its modulation have been carried out on fear motivated behaviors, possibly because of their applicability to the therapy of PTSD. A role for d-serine and the glycine site of NMDA receptors has been ascertained in two forms of extinction in the ventromedial prefrontal cortex, basolateral amygdala and dorsal hippocampus. The serine analog, d-cycloserine, has received clinical trials as an enhancer of extinction. The brain histaminergic system acting via H2 receptors, and the endocannabinoid system using CB1 receptors in the ventromedial prefrontal cortex, hippocampus and basolateral amygdala enhance extinction. Dopaminergic D1 and ß-noradrenergic receptors also modulate extinction by actions on these three structures. Isolated findings suggest roles for on serotonin-1A, dopaminergic-D2 and a- and ß-noradrenergic receptors in extinction modulation. Importantly, behavioral tagging and capture mechanisms in the hippocampus have been shown to play a major modulatory role in extinction. In addition, extinction of at least one aversive task (inhibitory avoidance) can be made state dependent on peripheral epinephrine.

  6. Melatonin as a selective estrogen enzyme modulator.

    PubMed

    Cos, S; González, A; Martínez-Campa, C; Mediavilla, M D; Alonso-González, C; Sánchez-Barceló, E J

    2008-12-01

    Melatonin exerts oncostatic effects on different kinds of tumors, especially on hormone-dependent breast cancer. The general conclusion is that melatonin, in vivo, reduces the incidence and growth of chemically-induced mammary tumors in rodents, and, in vitro, inhibits the proliferation and invasiveness of human breast cancer cells. Both studies support the hypothesis that melatonin inhibits the growth of breast cancer by interacting with estrogen-signaling pathways through three different mechanisms: (a) the indirect neuroendocrine mechanism which includes the melatonin down-regulation of the hypothalamic-pituitary-reproductive axis and the consequent reduction of circulating levels of gonadal estrogens, (b) direct melatonin actions at tumor cell level by interacting with the activation of the estrogen receptor, thus behaving as a selective estrogen receptor modulator (SERM), and (c) the regulation of the enzymes involved in the biosynthesis of estrogens in peripheral tissues, thus behaving as a selective estrogen enzyme modulator (SEEM). As melatonin reduces the activity and expression of aromatase, sulfatase and 17beta-hydroxysteroid dehydrogenase and increases the activity and expression of estrogen sulfotransferase, it may protect mammary tissue from excessive estrogenic effects. Thus, a single molecule has both SERM and SEEM properties, one of the main objectives desired for the breast antitumoral drugs. Since the inhibition of enzymes involved in the biosynthesis of estrogens is currently one of the first therapeutic strategies used against the growth of breast cancer, melatonin modulation of different enzymes involved in the synthesis of steroid hormones makes, collectively, this indolamine an interesting anticancer drug in the prevention and treatment of estrogen-dependent mammary tumors.

  7. Trimebutine as a modulator of gastrointestinal motility.

    PubMed

    Lee, Hyun-Tai; Kim, Byung Joo

    2011-06-01

    Trimebutine has been used for treatment of both hypermotility and hypomotility disorders of the gastrointestinal (GI) tract, such as irritable bowel syndrome. In this issue, Tan et al. (2011) examined the concentration-dependent dual effects of trimebutine on colonic motility in guinea pig. The authors suggested that trimebutine attenuated colonic motility mainly through the inhibition of L-type Ca(2+) channels at higher concentrations, whereas, at lower concentrations, it depolarized membrane potentials by reducing BK(ca) currents, resulting in the enhancement of the muscle contractions. Trimebutine might be a plausible modulator of GI motility, which gives an insight in developing new prokinetic agents. Further studies to elucidate the effects of trimebutine on the interstitial cells of Cajal, the pacemaker in GI muscles would promote the therapeutic benefits as a GI modulator. PMID:21725804

  8. Module bay with directed flow

    DOEpatents

    Torczynski, John R.

    2001-02-27

    A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.

  9. Ouabain modulates epithelial cell tight junction

    PubMed Central

    Larre, Isabel; Lazaro, Amparo; Contreras, Ruben G.; Balda, Maria S.; Matter, Karl; Flores-Maldonado, Catalina; Ponce, Arturo; Flores-Benitez, David; Rincon-Heredia, Ruth; Padilla-Benavides, Teresita; Castillo, Aída; Shoshani, Liora; Cereijido, Marcelino

    2010-01-01

    Epithelial cells treated with high concentrations of ouabain (e.g., 1 μM) retrieve molecules involved in cell contacts from the plasma membrane and detach from one another and their substrates. On the basis of this observation, we suggested that ouabain might also modulate cell contacts at low, nontoxic levels (10 or 50 nM). To test this possibility, we analyzed its effect on a particular type of cell–cell contact: the tight junction (TJ). We demonstrate that at concentrations that neither inhibit K+ pumping nor disturb the K+ balance of the cell, ouabain modulates the degree of sealing of the TJ as measured by transepithelial electrical resistance (TER) and the flux of neutral 3 kDa dextran (JDEX). This modulation is accompanied by changes in the levels and distribution patterns of claudins 1, 2, and 4. Interestingly, changes in TER, JDEX, and claudins behavior are mediated through signal pathways containing ERK1/2 and c-Src, which have distinct effects on each physiological parameter and claudin type. These observations support the theory that at low concentrations, ouabain acts as a modulator of cell–cell contacts. PMID:20534449

  10. GABAB receptors modulate NMDA receptor calcium signals in dendritic spines.

    PubMed

    Chalifoux, Jason R; Carter, Adam G

    2010-04-15

    Metabotropic GABA(B) receptors play a fundamental role in modulating the excitability of neurons and circuits throughout the brain. These receptors influence synaptic transmission by inhibiting presynaptic release or activating postsynaptic potassium channels. However, their ability to directly influence different types of postsynaptic glutamate receptors remains unresolved. Here we examine GABA(B) receptor modulation in layer 2/3 pyramidal neurons from the mouse prefrontal cortex. We use two-photon laser-scanning microscopy to study synaptic modulation at individual dendritic spines. Using two-photon optical quantal analysis, we first demonstrate robust presynaptic modulation of multivesicular release at single synapses. Using two-photon glutamate uncaging, we then reveal that GABA(B) receptors strongly inhibit NMDA receptor calcium signals. This postsynaptic modulation occurs via the PKA pathway and does not affect synaptic currents mediated by AMPA or NMDA receptors. This form of GABA(B) receptor modulation has widespread implications for the control of calcium-dependent neuronal function.

  11. Basic memory module

    NASA Technical Reports Server (NTRS)

    Tietze, F. C.

    1974-01-01

    Construction and electrical characterization of the 4096 x 2-bit Basic Memory Module (BMM) are reported for the Space Ultrareliable Modular Computer (SUMC) program. The module uses four 2K x 1-bit N-channel FET, random access memory chips, called array chips, and two sense amplifier chips, mounted and interconnected on a ceramic substrate. Four 5% tolerance power supplies are required. At the Module, the address, chip select, and array select lines require a 0-8.5 V MOS signal level. The data output, read-strobe, and write-enable lines operate at TTl levels. Although the module is organized as 4096 x 2 bits, it can be used in a 8196 x 1-bit application with appropriate external connections. A 4096 x 1-bit organization can be obtained by depopulating chips.

  12. GREET Pretreatment Module

    SciTech Connect

    Adom, Felix K.; Dunn, Jennifer B.; Han, Jeongwoo

    2014-09-01

    A wide range of biofuels and biochemicals can be produced from biomass via different pretreatment technologies that yield sugars. This report documents the material and energy flows that occur when fermentable sugars from four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar) are produced via dilute acid pretreatment and ammonia fiber expansion. These flows are documented for inclusion in the pretreatment module of the Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. Process simulations of each pretreatment technology were developed in Aspen Plus. Material and energy consumption data from Aspen Plus were then compiled in the GREET pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

  13. Module encapsulation technology

    NASA Technical Reports Server (NTRS)

    Willis, P.

    1986-01-01

    The identification and development techniques for low-cost module encapsulation materials were reviewed. Test results were displayed for a variety of materials. The improved prospects for modeling encapsulation systems for life prediction were reported.

  14. Digital optical conversion module

    DOEpatents

    Kotter, D.K.; Rankin, R.A.

    1988-07-19

    A digital optical conversion module used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer. 2 figs.

  15. Digital optical conversion module

    DOEpatents

    Kotter, Dale K.; Rankin, Richard A.

    1991-02-26

    A digital optical conversion module used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer.

  16. Columbus pressurized module verification

    NASA Technical Reports Server (NTRS)

    Messidoro, Piero; Comandatore, Emanuele

    1986-01-01

    The baseline verification approach of the COLUMBUS Pressurized Module was defined during the A and B1 project phases. Peculiarities of the verification program are the testing requirements derived from the permanent manned presence in space. The model philosophy and the test program have been developed in line with the overall verification concept. Such critical areas as meteoroid protections, heat pipe radiators and module seals are identified and tested. Verification problem areas are identified and recommendations for the next development are proposed.

  17. Firefighting module development

    NASA Astrophysics Data System (ADS)

    Burns, R. A.

    1981-10-01

    The firefighting module is a lightweight, compact, self contained, helicopter-transportable unit for fighting harbor and other specialty fires as well as for use in emergency water pumping applications. Units were fabricated and tested. A production type unit is undergoing an inservice evaluation and demonstration program at the port of St Louis. The primary purpose is to promote enhanced harbor fire protection at inland and coastal ports. The module and its development are described.

  18. Photovoltaic module reliability workshop

    SciTech Connect

    Mrig, L.

    1990-01-01

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986--1990. The reliability Photo Voltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warranties available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the US, PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  19. Second generation SLAC modulator

    SciTech Connect

    Donaldson, A.R.; Cron, J.C.; Hanselman, R.R.

    1986-06-01

    The Stanford Linear Accelerator Laboratory has undertaken the construction of a single pass electron-positron collider. In order to reach required beam energy 235 new klystrons needed upgraded modulator systems. The collider will use 50 GeV electrons and positrons. The increase in accelerator energy from the present 30 GeV necessitates the replacement of existing 35 MW klystrons with new 67 MW units. The doubling of klystron output power required a redesign of the modulator system. The 67 MW klystron needs a 350 kV beam voltage pulse with a 3.7 ..mu..s pulse width. A new pulse transformer was designed to deliver the increased voltage and pulse width. Pulse cable design was evaluated to obtain increased reliability of that critical element. The modulator, with the exception of its power supply, was rebuilt to produce the required power increase while enhancing reliability and improving maintainability. An investigation of present thyratron switch tube performance under the new operating conditions resulted in agitation and some warranted panic but these conditions were mitigated after several successful experiments and some evolutionary narrowing of the klystron pulse width. The discussion will cover the upgraded modulator system specifications and some details of the new pulse transformer tank, pulse cable, modulator, and modulator switch tube.

  20. Response inhibition and its relation to multidimensional impulsivity.

    PubMed

    Wilbertz, Tilmann; Deserno, Lorenz; Horstmann, Annette; Neumann, Jane; Villringer, Arno; Heinze, Hans-Jochen; Boehler, Carsten N; Schlagenhauf, Florian

    2014-12-01

    Impulsivity is a multidimensional construct that has been suggested as a vulnerability factor for several psychiatric disorders, especially addiction disorders. Poor response inhibition may constitute one facet of impulsivity. Trait impulsivity can be assessed by self-report questionnaires such as the widely used Barratt Impulsiveness Scale (BIS-11). However, regarding the multidimensionality of impulsivity different concepts have been proposed, in particular the UPPS self-report questionnaire ('Urgency', 'Lack of Premeditation', 'Lack of Perseverance', 'Sensation Seeking') that is based on a factor analytic approach. The question as to which aspects of trait impulsivity map on individual differences of the behavioral and neural correlates of response inhibition so far remains unclear. In the present study, we investigated 52 healthy individuals that scored either very high or low on the BIS-11 and underwent a reward-modulated Stop-signal task during fMRI. Neither behavioral nor neural differences were observed with respect to high- and low-BIS groups. In contrast, UPPS subdomain Urgency best explained inter-individual variability in SSRT scores and was further negatively correlated to right IFG/aI activation in 'Stop>Go' trials - a key region for response inhibition. Successful response inhibition in rewarded compared to nonrewarded stop trials yielded ventral striatal (VS) activation which might represent a feedback signal. Interestingly, only participants with low Urgency scores were able to use this VS feedback signal for better response inhibition. Our findings indicate that the relationship of impulsivity and response inhibition has to be treated carefully. We propose Urgency as an important subdomain that might be linked to response inhibition as well as to the use of reward-based neural signals. Based on the present results, further studies examining the influence of impulsivity on psychiatric disorders should take into account Urgency as an important

  1. Pain inhibits pain; human brainstem mechanisms.

    PubMed

    Youssef, A M; Macefield, V G; Henderson, L A

    2016-01-01

    Conditioned pain modulation is a powerful analgesic mechanism, occurring when a painful stimulus is inhibited by a second painful stimulus delivered at a different body location. Reduced conditioned pain modulation capacity is associated with the development of some chronic pain conditions and the effectiveness of some analgesic medications. Human lesion studies show that the circuitry responsible for conditioned pain modulation lies within the caudal brainstem, although the precise nuclei in humans remain unknown. We employed brain imaging to determine brainstem sites responsible for conditioned pain modulation in 54 healthy individuals. In all subjects, 8 noxious heat stimuli (test stimuli) were applied to the right side of the mouth and brain activity measured using functional magnetic resonance imaging. This paradigm was then repeated. However, following the fourth noxious stimulus, a separate noxious stimulus, consisting of an intramuscular injection of hypertonic saline into the leg, was delivered (conditioning stimulus). During this test and conditioning stimulus period, 23 subjects displayed conditioned pain modulation analgesia whereas 31 subjects did not. An individual's analgesic ability was not influenced by gender, pain intensity levels of the test or conditioning stimuli or by psychological variables such as pain catastrophizing or fear of pain. Brain images were processed using SPM8 and the brainstem isolated using the SUIT toolbox. Significant increases in signal intensity were determined during each test stimulus and compared between subjects that did and did not display CPM analgesia (p<0.05, small volume correction). The expression of analgesia was associated with reduction in signal intensity increases during each test stimulus in the presence of the conditioning stimulus in three brainstem regions: the caudalis subdivision of the spinal trigeminal nucleus, i.e., the primary synapse, the region of the subnucleus reticularis dorsalis and in the

  2. "Smart" Sensor Module

    NASA Technical Reports Server (NTRS)

    Mahajan, Ajay

    2007-01-01

    An assembly that contains a sensor, sensor-signal-conditioning circuitry, a sensor-readout analog-to-digital converter (ADC), data-storage circuitry, and a microprocessor that runs special-purpose software and communicates with one or more external computer(s) has been developed as a prototype of "smart" sensor modules for monitoring the integrity and functionality (the "health") of engineering systems. Although these modules are now being designed specifically for use on rocket-engine test stands, it is anticipated that they could also readily be designed to be incorporated into health-monitoring subsystems of such diverse engineering systems as spacecraft, aircraft, land vehicles, bridges, buildings, power plants, oilrigs, and defense installations. The figure is a simplified block diagram of the "smart" sensor module. The analog sensor readout signal is processed by the ADC, the digital output of which is fed to the microprocessor. By means of a standard RS-232 cable, the microprocessor is connected to a local personal computer (PC), from which software is downloaded into a randomaccess memory in the microprocessor. The local PC is also used to debug the software. Once the software is running, the local PC is disconnected and the module is controlled by, and all output data from the module are collected by, a remote PC via an Ethernet bus. Several smart sensor modules like this one could be connected to the same Ethernet bus and controlled by the single remote PC. The software running in the microprocessor includes driver programs for operation of the sensor, programs that implement self-assessment algorithms, programs that implement protocols for communication with the external computer( s), and programs that implement evolutionary methodologies to enable the module to improve its performance over time. The design of the module and of the health-monitoring system of which it is a part reflects the understanding that the main purpose of a health

  3. A nanoparticle-based epigenetic modulator for efficient gene modulation

    NASA Astrophysics Data System (ADS)

    Pongkulapa, Thanapat

    Modulation of gene expression through chromatin remodeling involves epigenetic mechanisms, such as histone acetylation. Acetylation is tightly regulated by two classes of enzymes, histone acetyltransferases (HATs) and histone deacetylases (HDACs). Molecules that can regulate these enzymes by altering (activating or inhibiting) their functions have become a valuable tool for understanding cell development and diseases. HAT activators, i.e. N-(4-Chloro-(3-trifluoromethyl)phenyl)-2-ethoxybenzamide (CTB), have shown a therapeutic potential for many diseases, including cancer and neurodegeneration. However, these compounds encounter a solubility and a membrane permeability issue, which restricts their full potential for practical usage, especially for in vivo applications. To address this issue, in this work, we developed a nanoparticle-based HAT activator CTB, named Au-CTB, by incorporating a new CTB analogue onto gold nanoparticles (AuNPs) along with a poly(ethylene glycol) moiety and a nuclear localization signal (NLS) peptide to assist with solubility and membrane permeability. We found that our new CTB analogue and Au-CTB could activate HAT activity. Significantly, an increase in potency to activate HAT activity by Au-CTB proved the effectiveness of using the nanoparticle delivery platform. In addition, the versatility of Au-CTB platform permits the attachment of multiple ligands with tunable ratios on the nanoparticle surface via facile surface functionalization of gold nanoparticles. Due to its high delivery efficiency and versatility, Au-CTB can be a powerful platform for applications in epigenetic regulation of gene expression.

  4. Universal enveloping crossed module of Leibniz crossed modules and representations

    NASA Astrophysics Data System (ADS)

    Casado, Rafael F.; García-Martínez, Xabier; Ladra, Manuel

    2016-03-01

    The universal enveloping algebra functor UL: Lb → Alg, defined by Loday and Pirashvili [1], is extended to crossed modules. Then we construct an isomorphism between the category of representations of a Leibniz crossed module and the category of left modules over its universal enveloping crossed module of algebras. Note that the procedure followed in the proof for the Lie case cannot be adapted, since the actor in the category of Leibniz crossed modules does not always exist.

  5. Direct spatial antenna modulation

    NASA Astrophysics Data System (ADS)

    Uhl, Brecken H.

    This body of work seeks to define Direct Spatial Antenna Modulation (DSAM) as a new and unique approach to data symbol modulation and phased array control by comparing and contrasting the technique to conventional approaches. A rigorous development of the theoretical and practical implications of the DSAM technique as a general approach are presented. The theoretical development of several DSAM examples are included. Implementation and measurement results for several prototypes based on DSAM principles are analyzed. The work concludes with a summary of the impact of the present DSAM developments and a proposal for additional investigation. Results are included that show equivalent measured bit error rate performance for DSAM as compared to conventional modulation for both two-state and four-state phase modulation. Measured beam control accuracy of a DSAM phased array is included, along with several other example DSAM phased array analyses. Supported by an analysis linking a DSAM technique with complete complex-plane modulation control, the DSAM concept is applied to a commercial antenna and an experiment demonstrates wideband phase control. Analytical and simulation results demonstrate joint beamforming and modulation in a DSAM array. Several implications of the results of the investigation are important to consider: 1. The DSAM approach represents a new way to treat the conventional relationship between modulation and antennas, and has been demonstrated through a significant number and variety of analyses, simulations, and experiments. 2. The DSAM approach takes direct advantage of inherent antenna radiating properties to perform conventionally non-antenna functions; the approach is in this way both enabled and limited. 3. The DSAM approach has been shown in several examples to offer beneficial engineering performance trade-offs with respect to architecture options, as well as important performance parameters such as power consumption, breadth of frequency

  6. Strictly homogeneous laterally complete modules

    NASA Astrophysics Data System (ADS)

    Chilin, V. I.; Karimov, J. A.

    2016-03-01

    Let A be a laterally complete commutative regular algebra and X be a laterally complete A-module. In this paper we introduce a notion of homogeneous and strictly homogeneous A-modules. It is proved that any homogeneous A-module is strictly homogeneous A-module, if the Boolean algebra of all idempotents in A is multi-σ-finite.

  7. Beneficial bacteria inhibit cachexia

    PubMed Central

    Varian, Bernard J.; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R.; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M.; Mirabal, Sheyla; Erdman, Susan E.

    2016-01-01

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  8. Beneficial bacteria inhibit cachexia.

    PubMed

    Varian, Bernard J; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M; Mirabal, Sheyla; Erdman, Susan E

    2016-03-15

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  9. Pharmacological Inhibition of FTO

    PubMed Central

    McMurray, Fiona; Demetriades, Marina; Aik, WeiShen; Merkestein, Myrte; Kramer, Holger; Andrew, Daniel S.; Scudamore, Cheryl L.; Hough, Tertius A.; Wells, Sara; Ashcroft, Frances M.; McDonough, Michael A.; Schofield, Christopher J.; Cox, Roger D.

    2015-01-01

    In 2007, a genome wide association study identified a SNP in intron one of the gene encoding human FTO that was associated with increased body mass index. Homozygous risk allele carriers are on average three kg heavier than those homozygous for the protective allele. FTO is a DNA/RNA demethylase, however, how this function affects body weight, if at all, is unknown. Here we aimed to pharmacologically inhibit FTO to examine the effect of its demethylase function in vitro and in vivo as a first step in evaluating the therapeutic potential of FTO. We showed that IOX3, a known inhibitor of the HIF prolyl hydroxylases, decreased protein expression of FTO (in C2C12 cells) and reduced maximal respiration rate in vitro. However, FTO protein levels were not significantly altered by treatment of mice with IOX3 at 60 mg/kg every two days. This treatment did not affect body weight, or RER, but did significantly reduce bone mineral density and content and alter adipose tissue distribution. Future compounds designed to selectively inhibit FTO’s demethylase activity could be therapeutically useful for the treatment of obesity. PMID:25830347

  10. Intensity modulated proton therapy.

    PubMed

    Kooy, H M; Grassberger, C

    2015-07-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed "pencil beams" of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak-the characteristic peak of dose at the end of range-combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radiotherapy or volumetric modulated arc therapy) with dose modulation along the beam axis as well as lateral, in-field, dose modulation. The clinical practice of IMPT further improves the healthy tissue vs target dose differential in comparison with X-rays and thus allows increased target dose with dose reduction elsewhere. In addition, heavy-charged-particle beams allow for the modulation of biological effects, which is of active interest in combination with dose "painting" within a target. The clinical utilization of IMPT is actively pursued but technical, physical and clinical questions remain. Technical questions pertain to control processes for manipulating pencil beams from the creation of the proton beam to delivery within the patient within the accuracy requirement. Physical questions pertain to the interplay between the proton penetration and variations between planned and actual patient anatomical representation and the intrinsic uncertainty in tissue stopping powers (the measure of energy loss per unit distance). Clinical questions remain concerning the impact and management of the technical and physical questions within the context of the daily treatment delivery, the clinical benefit of IMPT and the biological response differential compared with X-rays against which clinical benefit will be judged. It is expected that IMPT will replace other modes of proton field delivery. Proton radiotherapy, since its first practice 50 years ago, always required the highest level of

  11. Intensity modulated proton therapy

    PubMed Central

    Grassberger, C

    2015-01-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed “pencil beams” of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak—the characteristic peak of dose at the end of range—combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radiotherapy or volumetric modulated arc therapy) with dose modulation along the beam axis as well as lateral, in-field, dose modulation. The clinical practice of IMPT further improves the healthy tissue vs target dose differential in comparison with X-rays and thus allows increased target dose with dose reduction elsewhere. In addition, heavy-charged-particle beams allow for the modulation of biological effects, which is of active interest in combination with dose “painting” within a target. The clinical utilization of IMPT is actively pursued but technical, physical and clinical questions remain. Technical questions pertain to control processes for manipulating pencil beams from the creation of the proton beam to delivery within the patient within the accuracy requirement. Physical questions pertain to the interplay between the proton penetration and variations between planned and actual patient anatomical representation and the intrinsic uncertainty in tissue stopping powers (the measure of energy loss per unit distance). Clinical questions remain concerning the impact and management of the technical and physical questions within the context of the daily treatment delivery, the clinical benefit of IMPT and the biological response differential compared with X-rays against which clinical benefit will be judged. It is expected that IMPT will replace other modes of proton field delivery. Proton radiotherapy, since its first practice 50 years ago, always required the

  12. Spatial Terahertz Modulator

    NASA Astrophysics Data System (ADS)

    Xie, Zhenwei; Wang, Xinke; Ye, Jiasheng; Feng, Shengfei; Sun, Wenfeng; Akalin, Tahsin; Zhang, Yan

    2013-11-01

    Terahertz (THz) technology is a developing and promising candidate for biological imaging, security inspection and communications, due to the low photon energy, the high transparency and the broad band properties of the THz radiation. However, a major encountered bottleneck is lack of efficient devices to manipulate the THz wave, especially to modulate the THz wave front. A wave front modulator should allow the optical or electrical control of the spatial transmission (or reflection) of an input THz wave and hence the ability to encode the information in a wave front. Here we propose a spatial THz modulator (STM) to dynamically control the THz wave front with photo-generated carriers. A computer generated THz hologram is projected onto a silicon wafer by a conventional spatial light modulator (SLM). The corresponding photo-generated carrier spatial distribution will be induced, which forms an amplitude hologram to modulate the wave front of the input THz beam. Some special intensity patterns and vortex beams are generated by using this method. This all-optical controllable STM is structure free, high resolution and broadband. It is expected to be widely used in future THz imaging and communication systems.

  13. Bunch identification module

    SciTech Connect

    Fox, J.D.

    1981-01-01

    This module provides bunch identification and timing signals for the PEP Interaction areas. Timing information is referenced to the PEP master oscillator, and adjusted in phase as a function of region. Identification signals are generated in a manner that allows observers in all interaction regions to agree on an unambiguous bunch identity. The module provides bunch identification signals via NIM level logic, upon CAMAC command, and through LED indicators. A front panel ''region select'' switch allows the same module to be used in all regions. The module has two modes of operation: a bunch identification mode and a calibration mode. In the identification mode, signals indicate which of the three bunches of electrons and positrons are interacting, and timing information about beam crossing is provided. The calibration mode is provided to assist experimenters making time of flight measurements. In the calibration mode, three distinct gating signals are referenced to a selected bunch, allowing three timing systems to be calibrated against a common standard. Physically, the bunch identifier is constructed as a single width CAMAC module. 2 figs., 1 tab.

  14. Bidirectional Modulation of Numerical Magnitude.

    PubMed

    Arshad, Qadeer; Nigmatullina, Yuliya; Nigmatullin, Ramil; Asavarut, Paladd; Goga, Usman; Khan, Sarah; Sander, Kaija; Siddiqui, Shuaib; Roberts, R E; Cohen Kadosh, Roi; Bronstein, Adolfo M; Malhotra, Paresh A

    2016-05-01

    Numerical cognition is critical for modern life; however, the precise neural mechanisms underpinning numerical magnitude allocation in humans remain obscure. Based upon previous reports demonstrating the close behavioral and neuro-anatomical relationship between number allocation and spatial attention, we hypothesized that these systems would be subject to similar control mechanisms, namely dynamic interhemispheric competition. We employed a physiological paradigm, combining visual and vestibular stimulation, to induce interhemispheric conflict and subsequent unihemispheric inhibition, as confirmed by transcranial direct current stimulation (tDCS). This allowed us to demonstrate the first systematic bidirectional modulation of numerical magnitude toward either higher or lower numbers, independently of either eye movements or spatial attention mediated biases. We incorporated both our findings and those from the most widely accepted theoretical framework for numerical cognition to present a novel unifying computational model that describes how numerical magnitude allocation is subject to dynamic interhemispheric competition. That is, numerical allocation is continually updated in a contextual manner based upon relative magnitude, with the right hemisphere responsible for smaller magnitudes and the left hemisphere for larger magnitudes.

  15. Bidirectional Modulation of Numerical Magnitude.

    PubMed

    Arshad, Qadeer; Nigmatullina, Yuliya; Nigmatullin, Ramil; Asavarut, Paladd; Goga, Usman; Khan, Sarah; Sander, Kaija; Siddiqui, Shuaib; Roberts, R E; Cohen Kadosh, Roi; Bronstein, Adolfo M; Malhotra, Paresh A

    2016-05-01

    Numerical cognition is critical for modern life; however, the precise neural mechanisms underpinning numerical magnitude allocation in humans remain obscure. Based upon previous reports demonstrating the close behavioral and neuro-anatomical relationship between number allocation and spatial attention, we hypothesized that these systems would be subject to similar control mechanisms, namely dynamic interhemispheric competition. We employed a physiological paradigm, combining visual and vestibular stimulation, to induce interhemispheric conflict and subsequent unihemispheric inhibition, as confirmed by transcranial direct current stimulation (tDCS). This allowed us to demonstrate the first systematic bidirectional modulation of numerical magnitude toward either higher or lower numbers, independently of either eye movements or spatial attention mediated biases. We incorporated both our findings and those from the most widely accepted theoretical framework for numerical cognition to present a novel unifying computational model that describes how numerical magnitude allocation is subject to dynamic interhemispheric competition. That is, numerical allocation is continually updated in a contextual manner based upon relative magnitude, with the right hemisphere responsible for smaller magnitudes and the left hemisphere for larger magnitudes. PMID:26879093

  16. Bidirectional Modulation of Numerical Magnitude

    PubMed Central

    Arshad, Qadeer; Nigmatullina, Yuliya; Nigmatullin, Ramil; Asavarut, Paladd; Goga, Usman; Khan, Sarah; Sander, Kaija; Siddiqui, Shuaib; Roberts, R. E.; Cohen Kadosh, Roi; Bronstein, Adolfo M.; Malhotra, Paresh A.

    2016-01-01

    Numerical cognition is critical for modern life; however, the precise neural mechanisms underpinning numerical magnitude allocation in humans remain obscure. Based upon previous reports demonstrating the close behavioral and neuro-anatomical relationship between number allocation and spatial attention, we hypothesized that these systems would be subject to similar control mechanisms, namely dynamic interhemispheric competition. We employed a physiological paradigm, combining visual and vestibular stimulation, to induce interhemispheric conflict and subsequent unihemispheric inhibition, as confirmed by transcranial direct current stimulation (tDCS). This allowed us to demonstrate the first systematic bidirectional modulation of numerical magnitude toward either higher or lower numbers, independently of either eye movements or spatial attention mediated biases. We incorporated both our findings and those from the most widely accepted theoretical framework for numerical cognition to present a novel unifying computational model that describes how numerical magnitude allocation is subject to dynamic interhemispheric competition. That is, numerical allocation is continually updated in a contextual manner based upon relative magnitude, with the right hemisphere responsible for smaller magnitudes and the left hemisphere for larger magnitudes. PMID:26879093

  17. NREL module energy rating methodology

    SciTech Connect

    Whitaker, C.; Newmiller, J.; Kroposki, B.

    1995-11-01

    The goals of this project were to develop a tool for: evaluating one module in different climates; comparing different modules; provide a Q&D method for estimating periodic energy production; provide an achievable module rating; provide an incentive for manufacturers to optimize modules to non-STC conditions; and to have a consensus-based, NREL-sponsored activity. The approach taken was to simulate module energy for five reference days of various weather conditions. A performance model was developed.

  18. Tailoring elastase inhibition with synthetic peptides.

    PubMed

    Vasconcelos, Andreia; Azoia, Nuno G; Carvalho, Ana C; Gomes, Andreia C; Güebitz, Georg; Cavaco-Paulo, Artur

    2011-09-01

    Chronic wounds are the result of excessive amounts of tissue destructive proteases such as human neutrophil elastase (HNE). The high levels of this enzyme found on those types of wounds inactivate the endogenous inhibitor barrier thus, the search for new HNE inhibitors is required. This work presents two new HNE inhibitor peptides, which were synthesized based on the reactive-site loop of the Bowman-Birk inhibitor protein. The results obtained indicated that these new peptides are competitive inhibitors for HNE and, the inhibitory activity can be modulated by modifications introduced at the N- and C-terminal of the peptides. Furthermore, these peptides were also able to inhibit elastase from a human wound exudate while showing no cytotoxicity against human skin fibroblasts in vitro, greatly supporting their potential application in chronic wound treatment.

  19. Adenosine inhibits glutamatergic input to basal forebrain cholinergic neurons

    PubMed Central

    Hawryluk, J. M.; Ferrari, L. L.; Keating, S. A.

    2012-01-01

    Adenosine has been proposed as an endogenous homeostatic sleep factor that accumulates during waking and inhibits wake-active neurons to promote sleep. It has been specifically hypothesized that adenosine decreases wakefulness and promotes sleep recovery by directly inhibiting wake-active neurons of the basal forebrain (BF), particularly BF cholinergic neurons. We previously showed that adenosine directly inhibits BF cholinergic neurons. Here, we investigated 1) how adenosine modulates glutamatergic input to BF cholinergic neurons and 2) how adenosine uptake and adenosine metabolism are involved in regulating extracellular levels of adenosine. Our experiments were conducted using whole cell patch-clamp recordings in mouse brain slices. We found that in BF cholinergic neurons, adenosine reduced the amplitude of AMPA-mediated evoked glutamatergic excitatory postsynaptic currents (EPSCs) and decreased the frequency of spontaneous and miniature EPSCs through presynaptic A1 receptors. Thus we have demonstrated that in addition to directly inhibiting BF cholinergic neurons, adenosine depresses excitatory inputs to these neurons. It is therefore possible that both direct and indirect inhibition may synergistically contribute to the sleep-promoting effects of adenosine in the BF. We also found that blocking the influx of adenosine through the equilibrative nucleoside transporters or inhibiting adenosine kinase and adenosine deaminase increased endogenous adenosine inhibitory tone, suggesting a possible mechanism through which adenosine extracellular levels in the basal forebrain are regulated. PMID:22357797

  20. Deep frequency modulation interferometry.

    PubMed

    Gerberding, Oliver

    2015-06-01

    Laser interferometry with pm/Hz precision and multi-fringe dynamic range at low frequencies is a core technology to measure the motion of various objects (test masses) in space and ground based experiments for gravitational wave detection and geodesy. Even though available interferometer schemes are well understood, their construction remains complex, often involving, for example, the need to build quasi-monolithic optical benches with dozens of components. In recent years techniques have been investigated that aim to reduce this complexity by combining phase modulation techniques with sophisticated digital readout algorithms. This article presents a new scheme that uses strong laser frequency modulations in combination with the deep phase modulation readout algorithm to construct simpler and easily scalable interferometers. PMID:26072834

  1. Power module assembly

    DOEpatents

    Campbell, Jeremy B.; Newson, Steve

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  2. Waveform Sampler CAMAC Module

    SciTech Connect

    Freytag, D.R.; Haller, G.M.; Kang, H.; Wang, J.

    1985-09-01

    A Waveform Sampler Module (WSM) for the measurement of signal shapes coming from the multi-hit drift chambers of the SLAC SLC detector is described. The module uses a high speed, high resolution analog storage device (AMU) developed in collaboration between SLAC and Stanford University. The AMU devices together with high speed TTL clocking circuitry are packaged in a hybrid which is also suitable for mounting on the detector. The module is in CAMAC format and provides eight signal channels, each recording signal amplitude versus time in 512 cells at a sampling rate of up to 360 MHz. Data are digitized by a 12-bit ADC with a 1 ..mu..s conversion time and stored in an on-board memory accessible through CAMAC.

  3. Reliability of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1986-01-01

    In order to assess the reliability of photovoltaic modules, four categories of known array failure and degradation mechanisms are discussed, and target reliability allocations have been developed within each category based on the available technology and the life-cycle-cost requirements of future large-scale terrestrial applications. Cell-level failure mechanisms associated with open-circuiting or short-circuiting of individual solar cells generally arise from cell cracking or the fatigue of cell-to-cell interconnects. Power degradation mechanisms considered include gradual power loss in cells, light-induced effects, and module optical degradation. Module-level failure mechanisms and life-limiting wear-out mechanisms are also explored.

  4. Modulated infrared radiant source

    NASA Astrophysics Data System (ADS)

    Stewart, W. F.; Edwards, S. F.; Vann, D. S.; McCormick, R. F.

    1981-06-01

    A modulated, infrared radiant energy source was developed to calibrate an airborne nadir-viewing pressure modulated radiometer to be used to detect from Earth orbit trace gases in the troposphere. The technique used an 8 cm long, 0.005 cm diameter platinum-iridium wire as an isothermal, thin line radiant energy source maintained at 1200 K. A + or - 20 K signal, oscillating at controllable frequencies from dc to 20 Hz, was superimposed on it. This periodic variation of the line source energy was used to verify the pressure modulated radiometer's capability to distinguish between the signal variations caused by the Earth's background surface and the signal from the atmospheric gases of interest.

  5. Thin film module development

    NASA Technical Reports Server (NTRS)

    Jester, T.

    1985-01-01

    The design of ARCO Solar, Inc.'s Genesis G100 photovoltaic module was driven by several criteria, including environmental stability (both electrical and mechanical), consumer aesthetics, low materials costs, and manufacturing ease. The module circuitry is designed as a 12 volt battery charger, using monolithic patterning techniques on a glass superstrate. This patterning and interconnect method proves amenable to high volume, low cost production throughput, and the use of glass serves the dual role of handling ease and availability. The mechanical design of the module centers on environmental stability. Packaging of the glass superstrate circuit must provide good resistance to thermal and humidity exposure along with hi-pot insulation and hailstone impact resistance. The options considered are given. Ethylene vinyl acetate (EVA) is chosen as the pottant material for its excellent weatherability.

  6. Measuring PV module delamination

    SciTech Connect

    Murphy, E.B.

    1980-09-22

    Delamination of the encapsulating pottant from both substrate and silicon cells in solar photovoltaic modules has been a common occurrence. While the extent of delamination is in some cases minor, there are other cases where appreciably large areas have been affected. At this time, most delaminated areas do not appear to cause electrical degradation of modules; however, keeping track of delamination growth and rate of growth is important and has been difficult. More accurate measurement of delamination has been achieved by using an acoustic digitizer to record the pattern of delamination. With the aid of a computer, software can be generated that shows the exact areas of delamination. By periodic measrement of those types of modules prone to delamination, growth rates can be documented.

  7. Deep frequency modulation interferometry.

    PubMed

    Gerberding, Oliver

    2015-06-01

    Laser interferometry with pm/Hz precision and multi-fringe dynamic range at low frequencies is a core technology to measure the motion of various objects (test masses) in space and ground based experiments for gravitational wave detection and geodesy. Even though available interferometer schemes are well understood, their construction remains complex, often involving, for example, the need to build quasi-monolithic optical benches with dozens of components. In recent years techniques have been investigated that aim to reduce this complexity by combining phase modulation techniques with sophisticated digital readout algorithms. This article presents a new scheme that uses strong laser frequency modulations in combination with the deep phase modulation readout algorithm to construct simpler and easily scalable interferometers.

  8. Modulated infrared radiant source

    NASA Technical Reports Server (NTRS)

    Stewart, W. F.; Edwards, S. F.; Vann, D. S.; Mccormick, R. F.

    1981-01-01

    A modulated, infrared radiant energy source was developed to calibrate an airborne nadir-viewing pressure modulated radiometer to be used to detect from Earth orbit trace gases in the troposphere. The technique used an 8 cm long, 0.005 cm diameter platinum-iridium wire as an isothermal, thin line radiant energy source maintained at 1200 K. A + or - 20 K signal, oscillating at controllable frequencies from dc to 20 Hz, was superimposed on it. This periodic variation of the line source energy was used to verify the pressure modulated radiometer's capability to distinguish between the signal variations caused by the Earth's background surface and the signal from the atmospheric gases of interest.

  9. Space Experiment Module (SEM)

    NASA Technical Reports Server (NTRS)

    Brodell, Charles L.

    1999-01-01

    The Space Experiment Module (SEM) Program is an education initiative sponsored by the National Aeronautics and Space Administration (NASA) Shuttle Small Payloads Project. The program provides nationwide educational access to space for Kindergarten through University level students. The SEM program focuses on the science of zero-gravity and microgravity. Within the program, NASA provides small containers or "modules" for students to fly experiments on the Space Shuttle. The experiments are created, designed, built, and implemented by students with teacher and/or mentor guidance. Student experiment modules are flown in a "carrier" which resides in the cargo bay of the Space Shuttle. The carrier supplies power to, and the means to control and collect data from each experiment.

  10. Quantitative velocity modulation spectroscopy

    NASA Astrophysics Data System (ADS)

    Hodges, James N.; McCall, Benjamin J.

    2016-05-01

    Velocity Modulation Spectroscopy (VMS) is arguably the most important development in the 20th century for spectroscopic study of molecular ions. For decades, interpretation of VMS lineshapes has presented challenges due to the intrinsic covariance of fit parameters including velocity modulation amplitude, linewidth, and intensity. This limitation has stifled the growth of this technique into the quantitative realm. In this work, we show that subtle changes in the lineshape can be used to help address this complexity. This allows for determination of the linewidth, intensity relative to other transitions, velocity modulation amplitude, and electric field strength in the positive column of a glow discharge. Additionally, we explain the large homogeneous component of the linewidth that has been previously described. Using this component, the ion mobility can be determined.

  11. Printed Module Interconnects

    SciTech Connect

    Stockert, Talysa R.; Fields, Jeremy D.; Pach, Gregory F.; Mauger, Scott A.; van Hest, Maikel F. A. M.

    2015-06-14

    Monolithic interconnects in photovoltaic modules connect adjacent cells in series, and are typically formed sequentially involving multiple deposition and scribing steps. Interconnect widths of 500 um every 10 mm result in 5% dead area, which does not contribute to power generation in an interconnected solar panel. This work expands on previous work that introduced an alternative interconnection method capable of producing interconnect widths less than 100 um. The interconnect is added to the module in a single step after deposition of the photovoltaic stack, eliminating the need for scribe alignment. This alternative method can be used for all types of thin film photovoltaic modules. Voltage addition with copper-indium-gallium-diselenide (CIGS) solar cells using a 2-scribe printed interconnect approach is demonstrated. Additionally, interconnect widths of 250 um are shown.

  12. Thin film module development

    NASA Astrophysics Data System (ADS)

    Jester, T.

    1985-10-01

    The design of ARCO Solar, Inc.'s Genesis G100 photovoltaic module was driven by several criteria, including environmental stability (both electrical and mechanical), consumer aesthetics, low materials costs, and manufacturing ease. The module circuitry is designed as a 12 volt battery charger, using monolithic patterning techniques on a glass superstrate. This patterning and interconnect method proves amenable to high volume, low cost production throughput, and the use of glass serves the dual role of handling ease and availability. The mechanical design of the module centers on environmental stability. Packaging of the glass superstrate circuit must provide good resistance to thermal and humidity exposure along with hi-pot insulation and hailstone impact resistance. The options considered are given. Ethylene vinyl acetate (EVA) is chosen as the pottant material for its excellent weatherability.

  13. γ-Secretase Inhibitors and Modulators

    PubMed Central

    Golde, Todd E.; Koo, Edward H.; Felsenstein, Kevin M.; Osborne, Barbara A.; Miele, Lucio

    2013-01-01

    γ-Secretase is a fascinating, multi-subunit, intramembrane-cleaving protease that is now being considered as a therapeutic target for a number of diseases. Potent, orally bioavailable γ-secretase inhibitors (GSIs) have been developed and tested in humans with Alzheimer's disease (AD) and cancer. Preclinical studies also suggest the therapeutic potential for GSIs in other disease conditions. However, due to inherent mechanism based-toxicity of non-selective inhibition of γ-secretase, clinical development of GSIs will require empirical testing with careful evaluation of benefit versus risk. In addition to GSIs, compounds referred to as γ-secretase modulators (GSMs) remain in development as AD therapeutics. GSMs do not inhibit γ-secretase, but modulate γ-secretase processivity and thereby shift the profile of the secreted amyloid β peptides (Aβ) peptides produced. Although GSMs are thought to have an inherently safe mechanism of action, their effects on substrates other than the amyloid β protein precursor (APP) have not been extensively investigated. Herein, we will review the current state of development of GSIs and GSMs and explore pertinent biological and pharmacological questions pertaining to the use of these agents for select indications. PMID:23791707

  14. Ghrelin inhibits sympathetic nervous activity in sepsis.

    PubMed

    Wu, Rongqian; Zhou, Mian; Das, Padmalaya; Dong, Weifeng; Ji, Youxin; Yang, Derek; Miksa, Michael; Zhang, Fangming; Ravikumar, Thanjavur S; Wang, Ping

    2007-12-01

    Our previous studies have shown that norepinephrine (NE) upregulates proinflammatory cytokines by activating alpha(2)-adrenoceptor. Therefore, modulation of the sympathetic nervous system represents a novel treatment for sepsis. We have also shown that a novel stomach-derived peptide, ghrelin, is downregulated in sepsis and that its intravenous administration decreases proinflammatory cytokines and mitigates organ injury. However, it remains unknown whether ghrelin inhibits sympathetic activity through central ghrelin receptors [i.e., growth hormone secretagogue receptor 1a (GHSR-la)] in sepsis. To study this, sepsis was induced in male rats by cecal ligation and puncture (CLP). Ghrelin was administered through intravenous or intracerebroventricular injection 30 min before CLP. Our results showed that intravenous administration of ghrelin significantly reduced the elevated NE and TNF-alpha levels at 2 h after CLP. NE administration partially blocked the inhibitory effect of ghrelin on TNF-alpha in sepsis. GHSR-la inhibition by the administration of a GHSR-la antagonist, [d-Arg(1),d-Phe(5), d-Trp(7,9),Leu(11)]substance P, significantly increased both NE and TNF-alpha levels even in normal animals. Markedly elevated circulating levels of NE 2 h after CLP were also significantly decreased by intracerebroventricular administration of ghrelin. Ghrelin's inhibitory effect on NE release was completely blocked by intracerebroventricular injection of the GHSR-1a antagonist or a neuropeptide Y (NPY)/Y(1) receptor antagonist. However, ghrelin's downregulatory effect on TNF-alpha release was only partially diminished by these agents. Thus ghrelin has sympathoinhibitory properties that are mediated by central ghrelin receptors involving a NPY/Y1 receptor-dependent pathway. Ghrelin's inhibitory effect on TNF-alpha production in sepsis is partially because of its modulation of the overstimulated sympathetic nerve activation.

  15. Growth inhibition of Candida by human oral epithelial cells.

    PubMed

    Steele, C; Leigh, J; Swoboda, R; Fidel, P L

    2000-11-01

    Oropharyngeal candidiasis (OPC) caused by Candida albicans is a significant problem in human immunodeficiency virus (HIV)-infected persons. Recognizing the paucity of information on innate and/or adaptive mucosal host defenses against C. albicans, we recently reported that human and nonhuman primate and mouse vaginal epithelial cells inhibit the growth of C. albicans in vitro. In the present study, oral epithelial cells collected from saliva of healthy volunteers and a purified oral epithelial cell line were found to inhibit blastoconidia and/or hyphal growth of several Candida species. Cell contact was a strict requirement for the epithelial cell anti-Candida activity; neither saliva nor culture supernatants alone inhibited Candida growth, and addition of saliva to the coculture did not modulate the epithelial cell activity. Finally, epithelial cell anti-Candida activity was significantly lower in HIV-infected persons with OPC. Together, these results suggest that oral epithelial cells may play a role in innate resistance against OPC.

  16. Flexible programmable logic module

    DOEpatents

    Robertson, Perry J.; Hutchinson, Robert L.; Pierson, Lyndon G.

    2001-01-01

    The circuit module of this invention is a VME board containing a plurality of programmable logic devices (PLDs), a controlled impedance clock tree, and interconnecting buses. The PLDs are arranged to permit systolic processing of a problem by offering wide data buses and a plurality of processing nodes. The board contains a clock reference and clock dis