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Find video protocols related to scientific articles indexed in Pubmed.
Myeloid expression of Adenosine A2A receptor suppresses T and NK cell responses in the solid tumor microenvironment.
Cancer Res.
PUBLISHED: 11-08-2014
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High concentrations of adenosine in tumor microenvironments inhibit anti-tumor cytotoxic lymphocyte responses. Although T cells express inhibitory adenosine A2A receptors (A2ARs) that suppress their activation and inhibit immune killing of tumors, a role for myeloid-cell A2ARs in suppressing the immune response to tumors has yet to be investigated. In this study we show that the growth of transplanted syngeneic B16F10 melanoma or Lewis lung carcinoma cells is slowed in Adora2af/f-LysMCre+/- mice, which selectively lack myeloid A2ARs. Reduced melanoma growth is associated with significant increases in MHCII and IL-12 expression in tumor-associated macrophages and with >90% reductions in IL-10 expression in tumor-associated macrophages, dendritic cells and Ly6C+ or Ly6G+ myeloid-derived suppressor cells. Myeloid deletion of A2ARs significantly increases CD44 expression on tumor-associated T cells and NK cells. Depletion of CD8+ T cells or NK cells in tumor-bearing mice indicates that both cell types initially contribute to slowing melanoma growth in mice lacking myeloid A2A receptors, but tumor suppression mediated by CD8+ T cells is more persistent. Myeloid-selective A2AR deletion significantly reduces lung metastasis of melanomas that express luciferase (for in vivo tracking) and ovalbumin (as a model antigen.
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Insulin renders diabetic rats resistant to acute ischemic stroke by arresting nitric oxide reaction with superoxide to form peroxynitrite.
J. Biomed. Sci.
PUBLISHED: 07-03-2014
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The functions of free radicals on the effects of insulin that result in protection against cerebral ischemic insult in diabetes remain undefined. This present study aims to explain the contradiction among nitric oxide (NO)/superoxide/peroxynitrite of insulin in amelioration of focal cerebral ischemia-reperfusion (FC I/R) injury in streptozotocin (STZ)-diabetic rats and to delineate the underlying mechanisms. Long-Evans male rats were divided into three groups (age-matched controls, diabetic, and diabetic treated with insulin) with or without being subjected to FC I/R injury.
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Hippocampal transcriptional dysregulation after renal ischemia and reperfusion.
Brain Res.
PUBLISHED: 04-24-2014
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Neurological complications contribute largely to the morbidity and mortality in patients with acute renal failure. In order to study pathophysiological complications of renal failure, a murine model of renal ischemia/reperfusion-induced acute kidney injury (AKI) was generated by 60min bilateral ischemia, and followed by 2h or 24h reperfusion (B-60'IRI). Compared to the sham-operated mice, B-60'IRI mice exhibited a significant inflammatory injury to remote brain. We found that serum and brain levels of KC, G-CSF and MCP-1 were significantly increased in B-60'IRI mice after 2h and 24h reperfusion when compared with sham-operated mice. Moreover, B-60'IRI mice exhibited increased numbers of activated microglial cells in the brain, and severe blood-brain barrier (BBB) permeability when compared with the control sham mice. The technology of cDNA microarray and quantitated RT-PCR are used to identify hippocampal genes whose expression is altered in response to AKI in B-60' IRI mice. The initiation of transcriptional abnormality was indicated by the finding that B-60' IRI mice exhibited upregulated mRNA levels of genes involved in inflammation, cell signaling, extracellular matrix and cell-cycle regulation and downregulated mRNA levels of genes involved in transporters, G protein-coupled receptor signaling, cell survival and chaperone. Our data suggest that renal IR contributes to a complicated hippocampal gene irregulation in inflammation and physiological homeostasis.
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Lack of interleukin-17 leads to a modulated micro-environment and amelioration of mechanical hypersensitivity after peripheral nerve injury in mice.
Pain
PUBLISHED: 03-17-2014
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Interleukin-17 (IL-17) is involved in a wide range of inflammatory disorders and in recruitment of inflammatory cells to injury sites. A recent study of IL-17 knock-out mice revealed that IL-17 contributes to neuroinflammation and neuropathic pain after peripheral nerve injury. Surprisingly, little is known of micro-environment modulation by IL-17 in injured sites and in pathologically related neuroinflammation and chronic neuropathic pain. Therefore, we investigated nociceptive sensitization, immune cell infiltration, myeloperoxidase (MPO) activity, and expression of multiple cytokines and opioid peptides in damaged nerves of wild-type (IL-17(+/+)) and IL-17 knock-out (IL-17(-/-)) mice after partial sciatic nerve ligation. Our results demonstrated that the IL-17(-/-) mice had less behavioral hypersensitivity after partial sciatic nerve ligation, and inflammatory cell infiltration and pro-inflammatory cytokine (tumor necrosis factor-?, IL-6, and interferon-?) levels in damaged nerves were significantly decreased, with the levels of anti-inflammatory cytokines IL-10 and IL-13, and expressions of enkephalin, ?-endorphin, and dynorphin were also decreased compared to those in wild-type control mice. In conclusion, we provided evidence that IL-17 modulates the micro-environment at the level of the peripheral injured nerve site and regulates progression of behavioral hypersensitivity in a murine chronic neuropathic pain model. The attenuated behavioral hypersensitivity in IL-17(-/-) mice could be a result of decreased inflammatory cell infiltration to the injured site, resulting in modulation of the pro- and anti-inflammatory cytokine milieu within the injured nerve. Therefore, IL-17 may be a critical component for neuropathic pain pathogenesis and a novel target for therapeutic intervention for this and other chronic pain states.
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Extracellular adenosine regulates naive T cell development and peripheral maintenance.
J. Exp. Med.
PUBLISHED: 10-21-2013
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Adenosine produced as a byproduct of metabolic activity is present in all tissues and produces dose-dependent suppression of TCR signaling. Naive T cell maintenance depends on inhibition of TCR signals by environmental sensors, which are yet to be fully defined. We produced mice with a floxed adenosine A2A receptor (A2AR) gene, Adora2a, and show that either global A2AR deletion or cre-mediated T cell deletion elicits a decline in the number of naive but not memory T cells. A2AR signaling maintains naive T cells in a quiescent state by inhibiting TCR-induced activation of the phosphatidylinositide 3-kinase (PI3K)-AKT pathway, thereby reducing IL-7R? down-regulation and naive T cell apoptosis. Patterns of IL-7R? expression on T cells in chimeric mice reconstituted with Adora2a(+/+) and Adora2a(-/-) bone marrow cells suggest that decreased IL-7R? in naive T cells is a cell-intrinsic consequence of Adora2a deletion. In addition, A2AR expression increases in early thymic T cell development and contributes to progression of double-negative thymic precursors to single-positive thymocytes with increased IL-7R? expression. Therefore, A2AR signaling regulates T cell development and maintenance to sustain normal numbers of naive T cells in the periphery.
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The immune aspect in neuropathic pain: role of chemokines.
Acta Anaesthesiol Taiwan
PUBLISHED: 08-05-2013
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Neuropathic pain is a pathological symptom experienced worldwide by patients suffering with nervous system dysfunction caused by various diseases. Treatment of neuropathic pain is always accompanied by a poor response and undesired adverse effects. Therefore, developing a novel "pain-kill" drug design strategy is critical in this field. Recent evidence demonstrates that neuroinflammation and immune response contributes to the development of neuropathic pain. Nerve damage can initiate inflammatory and immune responses, as evidenced by the upregulation of cytokines and chemokines. In this paper, we demonstrated that different chemokines and chemokine receptors (e.g., CX3CL1/CX3CR1, CCL2/CCR2, CCL3/CCR1, CCL4/CCR5 and CCL5/CCR5) serve as mediators for neuron-glia communication subsequently modulate nociceptive signal transmission. By extensively understanding the role of chemokines in neurons and glial cells in nociceptive signal transmission, a novel strategy for a target-specific drug design could be developed.
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The essential role of endothelial nitric oxide synthase activation in insulin-mediated neuroprotection against ischemic stroke in diabetes.
J. Vasc. Surg.
PUBLISHED: 03-06-2013
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BACKGROUND: Stroke patients with diabetes have a higher mortality rate, worse neurologic outcome, and more severe disability than those without diabetes. Results from clinical trials comparing the outcomes of stroke seen with intensive glycemic control in diabetic individuals are conflicting. Therefore, the present study was aimed to identify the key factor involved in the neuroprotective action of insulin beyond its hypoglycemic effects in streptozotocin-diabetic rats with ischemic stroke. METHODS: Long-Evans male rats were divided into three groups (control, diabetes, and diabetes treated with insulin) and subjected to focal cerebral ischemia-reperfusion (FC I/R) injury. RESULTS: Hyperglycemia aggravated FC I/R injuries with an increase in cerebral infarction and neurologic deficits, inhibition of glucose uptake and membrane-trafficking activity of glucose transporter 1, and reduction of Akt and endothelial nitric oxide synthase (eNOS) phosphorylation in the cerebrum. Insulin treatment alleviated hyperglycemia and the symptoms of diabetes in streptozotocin-diabetic rats. Insulin administration also significantly decreased cerebral infarction and neurologic deficits and increased phosphorylation of Akt and eNOS protein in the cerebrum of FC I/R-injured diabetic rats. However, the glucose uptake and membrane trafficking activity of glucose transporter 1 in the cerebrum were not restored by insulin treatment. Coadministration of the eNOS inhibitor, N-iminoethyl-L-ornithine, with insulin abrogated beneficial effects of insulin on cerebral infarct volume and neurologic deficits in FC I/R-injured diabetic rats without affecting the hypoglycemic action of insulin. CONCLUSIONS: These results suggest that eNOS activation is required for the neuroprotection of insulin against ischemic stroke in patients with diabetes.
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Spatial and temporal analysis of nociception-related spinal cord matrix metalloproteinase expression in a murine neuropathic pain model.
J Chin Med Assoc
PUBLISHED: 03-05-2013
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Although the mammalian central nervous system contains numerous matrix metalloproteinases (MMPs), the significance of each MMP relative to nociception remains obscure. Working from the hypothesis that MMPs may be involved in activity-dependent reorganization during neuronal modulation, we explored the role of each MMP following neuropathological injury by establishing MMP expression profiles in a murine model for neuropathic pain.
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P-selectin is required for neutrophils and macrophage infiltration into injured site and contributes to generation of behavioral hypersensitivity following peripheral nerve injury in mice.
Pain
PUBLISHED: 01-21-2013
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Growing evidence suggests that leukocyte extravasation is initiated by the interaction of selectins with their ligands; as well as an essential role for P-selectin in the initial recruitment of inflammatory cells to sites of inflammation. In this study, P-selectin-deficient (P-sel-/-) mice were used to test the hypothesis that lack of P-selectin would attenuate the recruitment of inflammatory cells to the site of inflammation, thereby modulating pain in a murine chronic neuropathic pain model. Nociceptive sensitization and the microenvironment of the peripheral injury site were studied in wild-type (P-sel+/+) and P-selectin-deficient (P-sel-/-) mice after partial sciatic nerve ligation (PSNL). Variables measured included myeloperoxidase (MPO) activity, several inflammatory cell infiltration profiles, cytokines, and endogenous opioid peptide expression in damaged nerves. Results indicate that behavioral hypersensitivity, MPO activity, and infiltration of neutrophils and macrophages were attenuated in P-sel-/- mice after PSNL. Proinflammatory cytokines, tumor necrosis factor ?, and interleukin (IL)-6, were reduced in damaged nerves following PSNL; however, several antiinflammatory cytokines - IL-1Ra, IL-4, and IL-10 - were significantly increased in P-sel-/- mice. In addition, endogenous opioid peptides mRNA was significantly lower in P-sel-/- mice compared with P-sel +/+ mice. The current results demonstrated that the absence of P-selectin in mice leads to an altered microenvironment that attenuated behavioral hypersensitivity. The specific role of P-selectin could have been a result of decreased neutrophils, as well as the accumulation of macrophages at the site of injury, which may subsequently modulate the inflammatory cytokine expression and impact behavioral hypersensitivity within the injured nerve.
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5-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-3,7-dimethoxy-4H-chromen-4-one (MSF-2) suppresses fMLP-mediated respiratory burst in human neutrophils by inhibiting phosphatidylinositol 3-kinase activity.
J. Cell. Physiol.
PUBLISHED: 05-17-2011
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Respiratory burst mediates crucial bactericidal mechanism in neutrophils. However, undesirable respiratory burst leads to pathological inflammation and tissue damage. This study investigates the effect and the underlying mechanism of 5-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-3,7-dimethoxy-4H-chromen-4-one (MSF-2), a lignan extracted from the fruit of Melicope Semecarprifolia, on fMLP-induced respiratory burst in human neutrophils and suggests a possible therapeutic approach to ameliorate disease associated with neutrophil hyperactivation. MSF-2 inhibited fMLP-induced neutrophil superoxide anion production, cathepsin G release and migration in human neutrophils isolated from healthy volunteers, reflecting inhibition of phosphatidylinositol 3-kinase (PI3K) activation. Specifically, PI3K/AKT activation results in migration, degranulation and superoxide anion production in neutrophils. MSF-2 suppresses PI3K activation and phosphatidylinositol (3,4,5)-trisphosphate (PIP3) production, and consequently inhibits downstream activation of PDK1 and AKT. Further, PI3K also stimulates respiratory burst via PLC-dependent elevation of intracellular calcium. MSF-2 reduces fMLP-mediated PLC?2 activation and intracellular calcium accumulation notably through extracellular calcium influx in a PI3K and PLC-dependent manner. However, MSF-2 is not a competitive or allosteric antagonist of fMLP. Additionally, in an in vivo study, MSF-2 prevents fMLP-induced neutrophil infiltration and inflammation in mice. In conclusion, MSF-2 opposes fMLP-mediated neutrophil activation and inflammation by inhibiting PI3K activation and subsequent activation of AKT and PLC?2.
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Inflammation confers dual effects on nociceptive processing in chronic neuropathic pain model.
Anesthesiology
PUBLISHED: 02-11-2011
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Although inflammation induces pain, immune cells also produce mediators that can effectively counteract it. To further elucidate the role of the immune response, we analyzed the relationship of pain behavior, several inflammatory signals, and opioid peptides using partial sciatic nerve ligation in mice at different levels of immunocompromise.
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Involvement of YC-1 in extracellular signal-regulated kinase action in rat cremasteric muscle.
J. Pharm. Pharmacol.
PUBLISHED: 10-05-2010
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The nitric oxide (NO)-soluble guanylate cyclase (sGC) signalling pathway is attributed to the prevention of ischaemia-reperfusion (I/R)-induced leucocyte-endothelium adhesive interactions. YC-1 (3-(5-hydroxymethyl-2-furyl)-1-benzylindazole), a NO-independent sGC activator, has been shown to exert cardiovascular benefits, but its action on leucocyte-endothelium interactions remains unknown. In this study, the direct effect and the underlying mechanism of the anti-adhesive action of YC-1 have been examined in cremasteric microcirculation.
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Insulin and resveratrol act synergistically, preventing cardiac dysfunction in diabetes, but the advantage of resveratrol in diabetics with acute heart attack is antagonized by insulin.
Free Radic. Biol. Med.
PUBLISHED: 08-06-2010
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Resveratrol (RSV), a natural phenolic compound, has been found to display cardiovascular protective and insulin-sensitizing properties. In this study, the effects of RSV and its combination with insulin on mortality, hemodynamics, insulin signaling, and nitrosative stress were compared in streptozotocin (STZ)-induced diabetic rats with or without acute myocardial ischemia/reperfusion (I/R) injury. Under normoxic conditions, cardiac systolic and diastolic functions and insulin-mediated Akt/GLUT4 (glucose transporter 4) activation were impaired in STZ-diabetic rats. The combination of RSV and insulin significantly prevented the above diabetes-associated abnormalities. Notwithstanding that, the diabetic state rendered the animals more susceptible to myocardial I/R injury, and the mortality rate and inducible nitric oxide synthase (iNOS)/nitrotyrosine protein expression and superoxide anion production were also further increased in I/R-injured diabetic hearts. In contrast, RSV treatment alone resulted in a lower mortality rate (from 62.5 to 18%) and better cardiac systolic function than its combination with insulin. RSV also inhibited iNOS/nitrotyrosine protein overexpression and superoxide anion overproduction in I/R-injured diabetic myocardium. Hyperglycemia, impairment of insulin signaling, overexpression of iNOS/nitrotyrosine, and superoxide anion overproduction were markedly rescued by the combination treatment, which did not show an improvement in mortality rate (30%) or cardiac performance over RSV treatment alone. These results indicate that insulin and RSV synergistically prevented cardiac dysfunction in diabetes and this may be in parallel with activation of the insulin-mediated Akt/GLUT4 signaling pathway. Although activation of the protective signal (Akt/GLUT4) and suppression of the adverse markers (iNOS, nitrotyrosine, and superoxide anion) were simultaneously observed in insulin and RSV combination treatment, insulin counteracted the advantage of RSV in diabetics with acute heart attack.
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Exogenous granulocyte colony-stimulating factor exacerbate pain-related behaviors after peripheral nerve injury.
J. Neuroimmunol.
PUBLISHED: 07-07-2010
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Previous studies have demonstrated that inflammatory cells produce several mediators that can effectively counteract pain. This study was designed to test the hypothesis that exogenous administration of recombinant mouse granulocyte-colony-stimulating factor (rmG-CSF) to enhance the recruitment of inflammatory cells to painful inflamed sites could attenuate pain in a chronic neuropathic pain model in mice. Our results indicate that treatment with rmG-CSF increased several cytokines and opioid peptides content; however, it did not attenuate but exacerbate neuropathic pain. Our study highlights the potent pro-inflammatory potential of G-CSF and suggests they may be targets for therapeutic intervention in chronic neuropathic pain.
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The effect of warmed ropivacaine to body temperature on epidural sensory block characteristics.
J Clin Anesth
PUBLISHED: 03-23-2010
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To determine whether warmed (body temperature) ropivacaine increases the speed of onset of sensory block of epidural anesthesia.
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Effect of warm lidocaine on the sensory onset of epidural anesthesia: a randomized trial.
Chang Gung Med J
PUBLISHED: 12-29-2009
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Administration of local anesthetics at body temperature has been reported to shorten the onset time of regional block; however, studies examining the effects of warmed lidocaine on the onset of epidural anesthesia are limited. Here, we ascertain whether warming lidocaine solution to body temperature shortens the time to onset of epidural anesthesia.
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Novel variants near the central domain of RYR1 in two malignant hyperthermia-susceptible families from Taiwan.
Anesth. Analg.
PUBLISHED: 09-19-2009
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Our primary objective was to detect malignant hyperthermia (MH)-susceptible persons and thereby prevent MH episodes. We identified variants in the ryanodine receptor isoform 1 using molecular pedigree analysis.
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Platelet function analyzer (PFA-100) offers higher sensitivity and specificity than thromboelastography (TEG) in detection of platelet dysfunction.
Acta Anaesthesiol Taiwan
PUBLISHED: 09-19-2009
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The development of advanced surgical procedures requires novel and early diagnostic techniques. One of the prime difficulties that need to be overcome is an abnormality in the coagulation system. The blood clot formation and fibrinolysis processes are very complicated and important perioperatively. However, most of the major surgeries, such as liver transplantation, use thromboelastography (TEG) for detection of coagulation abnormalities, even though TEG is not actually an ideal option. Therefore, we compared the sensitivity and specificity of the platelet function analyzer (PFA-100) and thromboelastogram (TEG) in predicting platelet dysfunction and bleeding risk.
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Hydroxyethyl starch interferes with human blood ex vivo coagulation, platelet function and sedimentation.
Acta Anaesthesiol Taiwan
PUBLISHED: 06-17-2009
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Hydroxyethyl starch (HES) solutions are widely used for intravascular volume expansion. In Taiwan, the medium molecular weight of HES 200/0.5 and HES 130/0.4 solutions are most commonly used. It has been demonstrated that HES may affect coagulation and platelet function significantly. However, the differential effects of each medium molecular weight HES on platelets remain poorly reported. Therefore, we studied the influence of the two HES solutions on platelet function in vitro by mixing whole blood with different proportions of HES 130 kD, HES 200 kD, and saline to determine the differences.
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Hemeoxygenase-1 upregulation is critical for sirtinol-mediated attenuation of lung injury after trauma-hemorrhage in a rodent model.
Anesth. Analg.
PUBLISHED: 05-19-2009
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Hemeoxygenase-1 induction in response to adverse circulatory conditions is protective. Our recent study has shown that administration of sirtinol attenuates hepatic injury in male Sprague-Dawley rats after trauma-hemorrhage; however, the mechanism by which sirtinol produces the salutary effects remains unknown. We hypothesized that sirtinol administration in male Sprague-Dawley rats after trauma-hemorrhage decreases cytokine production and protects against lung injury through a hemeoxygenase-1 related pathway.
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Splitomicin suppresses human platelet aggregation via inhibition of cyclic AMP phosphodiesterase and intracellular Ca++ release.
Thromb. Res.
PUBLISHED: 02-11-2009
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Splitomicin is derived from beta-naphthol and is an inhibitor of Silent Information Regulator 2 (SIR2). Its naphthoic moiety might be responsible for its inhibitory effects on platelets. The major goal of our study was to examine possible mechanisms of action of splitomicin on platelet aggregation in order to promote development of a novel anti-platelet aggregation therapy for cardiovascular and cerebrovascular diseases. To study the inhibitory effects of splitomicin on platelet aggregation, we used washed human platelets, and monitored platelet aggregation and ATP release induced by thrombin (0.1 U/ml), collagen (2 microg/ml), arachidonic acid (AA) (0.5 mM), U46619 (2 microM) or ADP (10 microM). Splitomicin inhibited platelet aggregation induced by thrombin, collagen, AA and U46619 with a concentration dependent manner. Splitomicin increased cAMP and this effect was enhanced when splitomicin (150 microM) was combined with PGE1 (0.5 microM). It did not further increase cAMP when combined with IBMX. This data indicated that splitomicin increases cAMP by inhibiting activity of phosphodiestease. In addition, splitomicin (300 microM) attenuated intracellular Ca(++) mobilization, and production of thromboxane B2 (TXB2) in platelets that was induced by thrombin, collagen, AA or U46619. The inhibitory mechanism of splitomicin on platelet aggregation may increase cyclic AMP levels via inhibition of cyclic AMP phosphodiesterase activity and subsequent inhibition of intracellular Ca(++) mobilization, TXB2 formation and ATP release.
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A new insight of anti-platelet effects of sirtinol in platelets aggregation via cyclic AMP phosphodiesterase.
Biochem. Pharmacol.
PUBLISHED: 01-15-2009
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Sirtinol, a cell permeable six-membered lactone ring, is derived from naphthol and potent inhibitor of SIR2 and its naphtholic may have the inhibitory effects on platelets aggregation. In this study, platelet function was examined by collagen/epinephrine (CEPI) and collagen/ADP-induced closure times using the PFA-100 system reveal that CEPI-CT and CADP-CT were prolonged by sirtinol. The platelets aggregation regulated by physiological agonists such as: thrombin, collagen and AA and U46619 were significantly inhibited by sirtinol. Increases cAMP level was observed when sirtinol treated with Prostaglandin E1 in washed platelets. Moreover, sirtinol attenuated intracellular Ca(2+) release and thromboxane B2 formation stimulated by thrombin, collagen, AA and U46619 in human washed platelets. This study indicated that sirtinol could inhibit the platelet aggregation induced by physiological agonists, AA and U46619. The mechanism of action may include an increase of cAMP level with enhanced VASP-Ser157 phosphorylation via inhibition of cAMP phosphodiesterase activity and subsequent inhibition of intracellular Ca(2+) mobilization, thromboxane A2 formation, and ATP release during the platelet aggregation.
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Comparison of the effects of atropine and labetalol on trigeminocardiac reflex-induced hemodynamic alterations during percutaneous microballoon compression of the trigeminal ganglion.
Acta Anaesthesiol Taiwan
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A significant abrupt drop in heart rate is the most frequent complication during percutaneous microballoon compression of the trigeminal ganglion. It is suggested that co-activation of the sympathetic and parasympathetic nervous systems plays an important role in this occurrence. We hypothesized that not only atropine, but also labetalol might be effective in preventing this cardiovascular reflex during percutaneous microballoon compression of the trigeminal ganglion.
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Peritoneal administration of Met-RANTES attenuates inflammatory and nociceptive responses in a murine neuropathic pain model.
J Pain
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The C-C motif chemokine ligand 5 (CCL5; also known as regulated on activation, normal T expressed and secreted, or RANTES) is a member of the CC family of chemokines that specifically attract and activate leukocytes to sites of inflammation. Although CCL5 has been implicated in the processing of pain, its detailed mechanisms of action are still unknown. In this study, we investigated the potential of the Met-RANTES, a selective CCL5 receptor antagonist, via peritoneal administration to modulate the recruitment of inflammatory cells in injured sites and attenuate nociceptive responses in a neuropathic pain model in mice. Nociceptive sensitization, immune cell infiltration, multiple cytokine secretion, and opioid peptide expression in damaged nerves were studied. Our results indicated that Met-RANTES-treated mice had less behavioral hypersensitivity after partial sciatic nerve ligation. Macrophage infiltration, pro-inflammatory cytokine (TNF?, IL-1?, IL-6, and IFN?) protein secretion, and enkephalin, ?-endorphin, and dynorphin mRNA expression in damaged nerves following partial sciatic nerve ligation were significantly decreased, and anti-inflammatory cytokine (IL-10) protein was significantly increased in Met-RANTES-treated mice. These results suggest that CCL5 is capable of regulating the microenvironment that controls behavioral hypersensitivity at the level of the peripheral injured site in a murine chronic neuropathic pain model.
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Dendritic cells tolerized with adenosine A?AR agonist attenuate acute kidney injury.
J. Clin. Invest.
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DC-mediated NKT cell activation is critical in initiating the immune response following kidney ischemia/reperfusion injury (IRI), which mimics human acute kidney injury (AKI). Adenosine is an important antiinflammatory molecule in tissue inflammation, and adenosine 2A receptor (A?AR) agonists protect kidneys from IRI through their actions on leukocytes. In this study, we showed that mice with A?AR-deficient DCs are more susceptible to kidney IRI and are not protected from injury by A?AR agonists. In addition, administration of DCs treated ex vivo with an A?AR agonist protected the kidneys of WT mice from IRI by suppressing NKT production of IFN-? and by regulating DC costimulatory molecules that are important for NKT cell activation. A?AR agonists had no effect on DC antigen presentation or on Tregs. We conclude that ex vivo A?AR-induced tolerized DCs suppress NKT cell activation in vivo and provide a unique and potent cell-based strategy to attenuate organ IRI.
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Levobupivacaine differentially suppresses platelet aggregation by modulating calcium release in a dose-dependent manner.
Acta Anaesthesiol Taiwan
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Levobupivacaine, an amide local anesthetic widely used in regional anesthesia, is reported in recent studies that it is a potent inhibitor of platelet functions. However, the concentrations of levobupivacaine were limitedly estimated in these reports. Additionally, the mechanisms by which it affects platelet function and blood coagulation is still not entirely known. The purpose of this study was to further investigate its effects on platelet function and the possible signaling mechanisms under various concentrations of levobupivacaine.
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The anti-aggregation effects of ondansetron on platelets involve IP3 signaling and MAP kinase pathway, but not 5-HT3-dependent pathway.
Thromb. Res.
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Ondansetron is a 5-HT3 receptor antagonist with potent antiemetic, analgesic, and antiphlogistic effects. Literature concerning 5-HT3 antagonists on platelets is limited. In this report we examined the pharmacological effects of ondansetron on human washed platelets. Platelet aggregation induced by thrombin (0.1 U/mL), collagen (2 ?g/mL), arachidonic acid (0.5mM), ADP (10 ?M), or U46619 (2 ?M) was observed. The effects of ondansetron on platelet aggregation and ATP release were investigated at different concentrations. Cytosolic Ca(2+) influx concentration, TXB2, IP3, and the levels of cAMP and cGMP were monitored, and flow cytometric analysis and immunoblotting were performed to investigate downstream signaling components. Our results showed that ondansetron, in a concentration-dependent manner, inhibited agonist-induced platelet aggregation. At 75 ?M, ondansetron significantly attenuated intracellular Ca(2+) mobilization, thromboxane B2 formation, and ATP release by human washed platelets activated by thrombin, collagen, or U46619, whereas it only partially attenuated arachidonic acid-driven platelet activation. Administration of ondansetron resulted in attenuated IP3 production in the washed platelets stimulated by thrombin, as determined by reduced IP1 levels, as well as diminished p38 and ERK2 phosphorylation in response to thrombin. No effect of ondansetron on the levels of either cAMP or cGMP in washed platelets was observed. Furthermore, ondansetron-mediated inhibition of platelet aggregation was not impacted by SR 57227A, the 5-HT3 agonist. Thus, rather than involving the 5-HT3-dependent pathway, the negative effect of ondansetron on platelet aggregation is instead manifested through the attenuation of agonist-induced IP3 production and MAPK (p38 and ERK2) phosphorylation that results in suppressed intracellular Ca(2+) mobilization, TXB2 formation, and ATP release.
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The indispensable role of CCR5 for in vivo suppressor function of tumor-derived CD103+ effector/memory regulatory T cells.
J. Immunol.
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CD103 is a marker for identification of effector/memory regulatory T cells (Tregs). CD103(+) Tregs are potent suppressors of tissue inflammation in several infectious diseases, autoimmune diseases, and cancers. However, the underlying mechanisms for this potent suppression ability remain unclear. The current study was designed to clarify this issue. Unexpectedly, we found both CD103(+) and CD103(-) Tregs had similar suppression capacity in vitro. We then chose a murine tumor model for investigation of the in vivo behavior of these Tregs. The suppression ability in vivo against the anti-tumor ability of CD8(+) T cells was restricted to CD103(+) Tregs although both Tregs had equal in vitro suppression ability. In addition, CD103(+) Tregs expressed significantly higher levels of CCR5 than those of CD103(-) Tregs and accumulated more in tumors than did CD103(-) Tregs. Furthermore, blockade of CCR5 signaling, either by CCR5(-/-)CD103(+) Tregs or by CCL5 knockdown tumor, could reduce the migration of CD103(+) Tregs into tumors and impair their in vivo suppression ability. In conclusion, these results indicate that the potent in vivo suppression ability of CD103(+) Tregs is due to the tissue-migration ability through CCR5 expression.
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Splitomicin inhibits fMLP-induced superoxide anion production in human neutrophils by activate cAMP/PKA signaling inhibition of ERK pathway.
Eur. J. Pharmacol.
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Splitomicin, is a cell-permeable lactone derived from naphthol and known to be a potent selective inhibitor of Sir2 (silent information regulator 2). Previous studies have demonstrated that naphtholic compounds possess an inhibitory effect on neutrophils. Here, we present our investigation on the inhibitory effects of splitomicin in human neutrophils. The primary goal of our study was to locate a possible candidate on inflammatory reactions and to hopefully develop a novel anti-inflammatory therapy. Neutrophils were prepared following standard procedures. Neutrophils induced by either fMLP (1 ?M) or PMA (100 nM) were observed using a flow cytometer and the intracellular production of superoxide anions was investigated at different splitomicin concentrations. The cytosolic Ca(++) influx concentration was measured using a fluorescence spectrophotometer, and Mac-1 expression was detected with a flow cytometer. The MAP kinases were measured using western blotting. Our results showed that splitomicin inhibited superoxide anion production by fMLP (1 ?M) and NaF (20mM) in a concentration-dependent manner (37.5-450 ?M). Splitomicin (300 and 450 ?M) also suppressed fMLP-induced intracellular calcium ion mobilization and extracellular-signal regulated kinase (ERK) phosphorylation. Moreover, splitomicin could inhibit fMLP-induced Mac-1 expression and increase cAMP levels in human neutrophils. Our data demonstrated that splitomicin exhibits a noticeable inhibitory effect on superoxide anion production in human neutrophils. This negative effect was well-correlated with increased cAMP levels via PKA activity and the subsequent inhibition of ERK (p42/p44) phosphorylation to decrease superoxide anion production.
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Absence of C-C motif chemokine ligand 5 in mice leads to decreased local macrophage recruitment and behavioral hypersensitivity in a murine neuropathic pain model.
Pain
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Accumulated evidence suggests that the C-C motif chemokine ligand 5 (CCL5) modulates migration of inflammatory cells in several pathological conditions. This study tested the hypothesis that lack of CCL5 would modulate the recruitment of inflammatory cells to painful, inflamed sites and could attenuate pain in a murine chronic neuropathic pain model. Nociceptive sensitization, immune cell infiltration, multiple cytokine expression, and opioid peptide expression in damaged nerves were studied in wild-type (CCL5 +/+) and CCL5-deficient (CCL5 -/-) mice after partial sciatic nerve ligation (PSNL). Results indicated that CCL5 -/- mice had less behavioral hypersensitivity after PSNL. Macrophage infiltration and proinflammatory cytokines (tumor necrosis factor-?, interleukin [IL]-1?, IL-6, and interferon-?) in damaged nerves following PSNL were significantly decreased in CCL5 -/- mice. Conversely, several antiinflammatory cytokine (IL-4 and IL-10) proteins were significantly increased in CCL5 -/- animals and the expression of enkephalin, ?-endorphin, and dynorphin mRNA was significantly lower than in wild-type control mice. These results represent the first evidence that CCL5 is capable of regulating the pathway that controls hyperalgesia at the level of the peripheral injured site in a murine chronic neuropathic pain model. We demonstrated that lack of CCL5 modulated cell infiltration and the proinflammatory milieu within the injured nerve. Attenuated behavioral hypersensitivity in CCL5 -/- mice observed in the current study could be a result of decreased macrophage infiltration, mobilization, and functional ability at injured sites. Collectively, the present study results suggest that CCL5 receptor antagonists may ultimately provide a novel class of analgesics for therapeutic intervention in chronic neuropathic pain.
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Tumor-derived chemokine CCL5 enhances TGF-?-mediated killing of CD8(+) T cells in colon cancer by T-regulatory cells.
Cancer Res.
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Chemokine CCL5/RANTES is highly expressed in cancer where it contributes to inflammation and malignant progression. In this study, we show that CCL5 plays a critical role in immune escape in colorectal cancer. We found that higher levels of CCL5 expression in human and murine colon tumor cells correlated with higher levels of apoptosis of CD8+ T cells and infiltration of T-regulatory cells (T(reg)). In mouse cells, RNA interference (RNAi)-mediated knockdown of CCL5 delayed tumor growth in immunocompetent syngeneic hosts but had no effect on tumor growth in immunodeficient hosts. Reduced tumor growth was correlated with a reduction in T(reg) infiltration and CD8(+) T-cell apoptosis in tumors. Notably, we found that CCL5 enhanced the cytotoxicity of T(reg) against CD8(+) T cells. We also found tumor growth to be diminished in mice lacking CCR5, a CCL5 receptor, where a similar decrease in both T(reg) cell infiltration and CD8(+) T-cell apoptosis was noted. TGF-? signaling blockade diminished apoptosis of CD8(+) T cells, implicating TGF-? as an effector of CCL5 action. In support of this concept, CCL5 failed to enhance the production of TGF-? by CCR5-deficient T(reg) or to enhance their cytotoxic effects against CD8(+) T cells. CCR5 signaling blockade also diminished the in vivo suppressive capacity of T(reg) in inhibiting the antitumor responses of CD8(+) T cells, in the same way as CCL5 signaling blockade. Together, our findings establish that CCL5/CCR5 signaling recruits T(reg) to tumors and enhances their ability to kill antitumor CD8(+) T cells, thereby defining a novel mechanism of immune escape in colorectal cancer.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.