prostaglandin-d2 and Brain-Ischemia

The present study was to investigate the role of microRNA (miR)-211-5p on cerebral ischemia-reperfusion injury (CIRI) and clarify its underlying mechanisms. Middle cerebral artery occlusion/reperfusion (MCAO/R) was operated on male Sprague Dawley (SD) rats, oxygen-glucose deprivation/reperfusion (OGD/R) was conducted on pheochromocytoma-12 (PC12) cells. Here, we found that miR-211-5p and Cyclooxygenase (COX2) expressions were altered in the plasma, cortex and hippocampus of MCAO/R-treated rats, as well as in the OGD/R-treaded PC12 cells. In vivo, overexpression of miR-211-5p resulted in decrease of infarct volumes, neurological deficit scores and histopathological damage. In vitro, miR-211-5p overexpression significantly decreased cell apoptosis and Lactate dehydrogenase (LDH) release rate, increased cell viability. Furthermore, our data showed that miR-211-5p overexpression markedly reduced the expressions of COX2 mRNA and protein, and the contents of Prostaglandin D2 (PGD2), PGE2, tumor necrosis factor-α (TNF-α) and Interleukin-1β (IL-1β). In addition, inhibition of COX2 significantly rescued the effects of miR-211-5p inhibitor. At last, dual luciferase experimental data showed that miR-211-5p regulated the mRNA stability of COX2 by directly binding to the 3'-untranslated region (3'-UTR) of COX2. In conclusion, our data suggested the neuroprotective effects of miR-211-5p on CIRI by targeting COX2.

Topics: Animals; Antagomirs; Apoptosis; Brain Ischemia; Cell Survival; Cerebral Cortex; Cyclooxygenase 2; Dinoprostone; Gene Expression Regulation; Glucose; Hippocampus; Infarction, Middle Cerebral Artery; Interleukin-1beta; L-Lactate Dehydrogenase; Male; MicroRNAs; Oxygen; PC12 Cells; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; RNA Stability; RNA, Messenger; Signal Transduction; Tumor Necrosis Factor-alpha

Peroxisome proliferator-activated receptor-gamma (PPAR-γ), a stress-induced transcription factor, protects neurons against ischemic stroke insult by reducing oxidative stress. NADPH oxidase (NOX) activation, a major driving force in ROS generation in the setting of reoxygenation/reperfusion, constitutes an important pathogenetic mechanism of ischemic brain damage. In the present study, both transient in vitro oxygen-glucose deprivation and in vivo middle cerebral artery (MCA) occlusion-reperfusion experimental paradigms of ischemic neuronal death were used to investigate the interaction between PPAR-γ and NOX. With pharmacological (PPAR-γ antagonist GW9662), loss-of-function (PPAR-γ siRNA), and gain-of-function (Ad-PPAR-γ) approaches, we first demonstrated that 15-deoxy-∆(12,14)-PGJ2 (15d-PGJ2), via selectively attenuating p22phox expression, inhibited NOX activation and the subsequent ROS generation and neuronal death in a PPAR-γ-dependent manner. Secondly, results of promoter analyses and subcellular localization studies further revealed that PPAR-γ, via inhibiting hypoxia-induced NF-κB nuclear translocation, indirectly suppressed NF-κB-driven p22phox transcription. Noteworthily, postischemic p22phox siRNA treatment not only reduced infarct volumes but also improved functional outcome. In summary, we report a novel transrepression mechanism involving PPAR-γ downregulation of p22phox expression to suppress the subsequent NOX activation, ischemic neuronal death, and brain infarct. Identification of a PPAR-γ → NF-κB → p22phox neuroprotective signaling cascade opens a new avenue for protecting the brain against ischemic insult.

Topics: Animals; Apoptosis; Base Sequence; Brain Ischemia; Cell Nucleus; Cells, Cultured; Cerebral Cortex; Cerebral Infarction; Cytochrome b Group; Cytosol; Down-Regulation; Glucose; Male; Mice; NADPH Oxidases; Neurons; NF-kappa B; Oxidation-Reduction; Oxygen; PPAR gamma; Promoter Regions, Genetic; Prostaglandin D2; Protein Binding; Protein Transport; Rats, Long-Evans; Reactive Oxygen Species; RNA, Small Interfering; Transcription, Genetic

Peroxisome proliferator-activated receptor-γ (PPAR-γ) has recently emerged as potential therapeutic agents for cerebral ischemia-reperfusion (I/R) injury because of anti-neuronal apoptotic actions. However, whether PPAR-γ activation mediates neuronal autophagy in such conditions remains unclear. Therefore, in this study, we investigated the role of PPAR-γ agonist 15-PGJ(2) on neuronal autophagy induced by I/R. The expression of autophagic-related protein in ischemic cortex such as LC3-II, Beclin 1, cathepsin-B and LAMP1 increased significantly after cerebral I/R injury. Furthermore, increased punctate LC3 labeling and cathepsin-B staining occurred in neurons. Treatment with PPAR-γ agonist 15d-PGJ(2) decreased not only autophagic-related protein expression in ischemic cortex, but also immunoreactivity of LC3 and cathepsin-B in neurons. Autophagic inhibitor 3-methyladenine (3-MA) decreased LC3-II levels, reduced the infarct volume, and mimicked some protective effect of 15d-PGJ(2) against cerebral I/R injury. These results indicate that PPAR-γ agonist 15d-PGJ(2) exerts neuroprotection by inhibiting neuronal autophagy after cerebral I/R injury. Although the molecular mechanisms underlying PPAR-γ agonist in mediating neuronal autophagy remain to be determined, neuronal autophagy may be a new target for PPAR-γ agonist treatment in cerebral I/R injury.

Topics: Animals; Autophagy; Brain Ischemia; Cathepsin B; Disease Models, Animal; Humans; Male; Mice; Microtubule-Associated Proteins; Neurons; Neuroprotective Agents; PPAR gamma; Prostaglandin D2; Reperfusion Injury

The cardiovascular complications reported to be associated with cyclooxygenase inhibitor use have shifted our focus toward prostaglandins and their respective receptors. Prostaglandin D(2) and its DP1 receptor have been implicated in various normal and pathologic conditions, but their role in stroke is still poorly defined. Here, we tested whether DP1 deletion aggravates N-methyl-D: -aspartic acid (NMDA)-induced acute toxicity and whether DP1 pharmacologic activation protects mice from acute excitotoxicity and transient cerebral ischemia. Moreover, since the elderly are more vulnerable to stroke-related damage than are younger patients, we tested the susceptibility of aged DP1 knockout (DP1(-/-)) mice to brain damage. We found that intrastriatal injection of 15 nmol NMDA caused significantly larger lesion volumes (27.2 +/- 6.4%) in young adult DP1(-/-) mice than in their wild-type counterparts. Additionally, intracerebroventricular pretreatment of wild-type mice with 10, 25, and 50 nmol of the DP1-selective agonist BW245C significantly attenuated the NMDA-induced lesion size by 19.5 +/- 5.0%, 39.6 +/- 7.7%, and 28.9 +/- 7.0%, respectively. The lowest tested dose of BW245C also was able to reduce middle cerebral artery occlusion-induced brain infarction size significantly (21.0 +/- 5.7%). Interestingly, the aggravated NMDA-induced brain damage was persistent in older DP1(-/-) mice as well. We conclude that the DP1 receptor plays an important role in attenuating brain damage and that selective targeting of this receptor could be considered as an adjunct therapeutic tool to minimize stroke damage.

Topics: Animals; Brain Ischemia; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Stroke

Inflammatory lipid mediators derived from arachidonic acid (AA) and docosahexaenoic acid (DHA) modify the pathophysiology of brain ischemia. The goal of this work was to investigate the formation of eicosanoids and docosanoids generated from AA and DHA, respectively, during no-flow cerebral ischemia. Rats were subjected to head-focused microwave irradiation 5 min following decapitation (complete ischemia) or prior to decapitation (controls). Brain lipids were extracted and analyzed by reverse-phase liquid chromatography-tandem mass spectrometry. After complete ischemia, brain AA, DHA, and docosapentaenoic acid concentrations increased 18-, 5- and 4-fold compared with controls, respectively. Prostaglandin E(2) (PGE(2)) and PGD(2) could not be detected in control microwaved rat brain, suggesting little endogenous PGE(2)/D(2) production in the brain in the absence of experimental manipulation. Concentrations of thromboxane B(2), E(2)/D(2)-isoprostanes, 5-hydroxyeicosatetraenoic acid (5-HETE), 5-oxo-eicosatetraenoic acid, and 12-HETE were significantly elevated in ischemic brains. In addition, DHA products such as mono-, di- and trihydroxy-DHA were detected in control and ischemic brains. Monohydroxy-DHA, identified as 17-hydroxy-DHA and thought to be the immediate precursor of neuroprotectin D(1), was 6.5-fold higher in ischemic than in control brain. The present study demonstrated increased formation of eicosanoids, E(2)/D(2)-IsoPs, and docosanoids following cerebral ischemia. A balance of these lipid mediators may mediate immediate events of ischemic injury and recovery.

Topics: Animals; Brain; Brain Chemistry; Brain Ischemia; Decapitation; Dinoprostone; Docosahexaenoic Acids; Eicosanoids; Isoprostanes; Male; Microwaves; Prostaglandin D2; Rats; Rats, Inbred F344

Hematopoietic prostaglandin D synthase is a key enzyme in synthesis of prostaglandin D. Hematopoietic prostaglandin D synthase is expressed in microglia of the developing mouse brain. This study determined the serial changes and cellular localization of hematopoietic prostaglandin D synthase, and its role in cerebral ischemia/reperfusion injury using C57BL/6 mice (n=84) and bone marrow chimera mice (n=16). The latter mice were selected based on their expression of enhanced green fluorescent protein in bone marrow/blood-derived monocytes/macrophages. The middle cerebral artery was occluded for 60 min, followed by reperfusion. Hematopoietic prostaglandin D synthase expression was examined by immunohistochemistry and Western blotting. Hematopoietic prostaglandin D synthase-positive cells were mainly expressed in the peri-ischemic area at 12 h (P<0.05) and 24 h (P<0.001) after reperfusion, while they were mostly found in the transition area at 48-72 h postreperfusion (P<0.001). There was a significant increase in staining intensity as well as number of hematopoietic prostaglandin D synthase-positive cells in the ischemic core at 5-7 (P<0.001) days postreperfusion. Hematopoietic prostaglandin D synthase-positive cells also co-expressed ionized calcium-binding adapter molecule 1, a marker of microglia/macrophages, and cyclooxygenase-2, but not markers of neurons, oligodendrocytes and astrocytes. Until 72 h postreperfusion, many enhanced green fluorescent protein-positive cells were negative for hematopoietic prostaglandin D synthase, but the number of hematopoietic prostaglandin D synthase-enhanced green fluorescent protein coexpressing cells increased significantly at 5-7 days after reperfusion. Our results indicate that hematopoietic prostaglandin D synthase is mainly produced by endogenous microglia until 72 h after reperfusion, but at 7 days after reperfusion, it is also produced by migrating bone marrow/blood-derived macrophages in the ischemic brain tissue. We speculate that hematopoietic prostaglandin D synthase in the brain has different functions during early and late phases of ischemia.

Topics: Animals; Brain; Brain Ischemia; Calcium-Binding Proteins; Cell Count; Cell Movement; Cell Proliferation; Cyclooxygenase 2; Green Fluorescent Proteins; Hematopoiesis; Intramolecular Oxidoreductases; Lipocalins; Macrophages; Male; Mice; Mice, Inbred C57BL; Microfilament Proteins; Microglia; Prostaglandin D2; Reperfusion Injury; Transplantation Chimera; Up-Regulation

Existing experimental evidence suggests that PPARgamma may play a beneficial role in neuroprotection from various brain pathologies. Here we found that focal cerebral ischemia induced by middle cerebral/common carotid arteries occlusion (MCA/CCAo) induced up-regulation of PPARgamma messenger RNA in the ischemic hemisphere as early as 6 h after the ischemic event. The increased PPARgamma mRNA expression was primarily associated with neurons in the ischemic penumbra, suggesting an important role for PPARgamma in neurons after ischemia. Intraventricular injection of 15d-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), a proposed endogenous PPARgamma agonist, into the ischemic rat brains significantly increased the PPARgamma-DNA-binding activity and reduced infarction volume at 24 h after reperfusion. We propose that PPARgamma up-regulation in response to ischemia may contribute to PPARgamma activation in the presence of PPARgamma agonists. Activation of PPARgamma in neurons at an early stage after ischemia may represent a pro-survival mechanism against ischemic injury.

Topics: Animals; Brain; Brain Ischemia; Cerebral Infarction; Electrophoretic Mobility Shift Assay; In Situ Hybridization; Injections, Intraventricular; Male; Neurons; Neuroprotective Agents; PPAR gamma; Prostaglandin D2; Rats; Rats, Long-Evans; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Up-Regulation

The 15-deoxyDelta prostaglandin J2 (15-dPGJ2) is an anti-inflammatory prostaglandin that has been proposed to be the endogenous ligand of peroxisome proliferator-activated receptor-gamma (PPARgamma), a nuclear receptor that can exert potent anti-inflammatory actions by repressing inflammatory genes when activated. It has been suggested that 15-dPGJ2 could be beneficial in neurological disorders in which inflammation contributes to cell death such as stroke.. We investigated the relationship between plasma levels of 15-dPGJ2 and early neurological deterioration (END), infarct volume, and neurologic outcome in 552 patients with an acute stroke admitted within 24 hours after symptoms onset.. Median [quartiles] plasma 15-dPGJ2 levels on admission were significantly higher in patients than in controls (60.5 [11.2 to 109.4] versus 5.0 [3.8 to 7.2] pg/mL; P<0.0001). Levels of this prostaglandin were also significantly higher in patients with vascular risk factors (history of hypertension or diabetes) and with atherothrombotic infarcts (113.9 [81.6 to 139.7] pg/mL), than in those with lacunar (58.7 [32.7 to 86.2] pg/mL), cardioembolic (12.1 [6.5 to 39.2] pg/mL), or undetermined origin infarcts (11.4 [5.6 to 24.3] pg/mL) (P<0.0001). In the subgroup of patients with atherothrombotic infarcts, the adjusted odds ratio of END and poor outcome for 1 pg/mL increase in 15-dPGJ2 were 0.95 (95% CI, 0.94 to 0.97) and 0.97 (95% CI, 0.96 to 0.98), respectively. In a generalized linear model, by 1 U increase in 15-dPGJ2, there was a reduction of 0.47 mL (95% CI, 0.32 to 0.63) in the mean estimated infarct volume.. Increased plasma 15-dPGJ2 concentration is associated with good early and late neurological outcome and smaller infarct volume. These findings suggest a neuroprotective effect of 15-dPGJ2 in atherothrombotic ischemic stroke.

Topics: Acute Disease; Aged; Anti-Inflammatory Agents; Brain Ischemia; Case-Control Studies; Female; Humans; Inflammation; Ligands; Male; Middle Aged; Nervous System Diseases; Odds Ratio; PPAR gamma; Prostaglandin D2; Regression Analysis; Stroke; Thrombosis; Time Factors; Treatment Outcome

Previously we found that some cyclopentenone prostaglandin derivatives promoted neurite outgrowth from PC12 cells and dorsal root ganglia explants in the presence of nerve growth factor; and so we referred to them as neurite outgrowth-promoting prostaglandins (NEPPs). In this study, NEPPs protected HT22 cells against oxidative glutamate toxicity. NEPP6, one of the most effective promoters of neurite outgrowth in PC12 cells, protected the cells most potently among NEPPs 1--10. Several derivatives, NEPPs 11--19, were newly synthesized based on the chemical structure of NEPP6. NEPP11 had a more potent neuroprotective effect than NEPP6. NEPP11 also prevented the death of cortical neurons induced by various stimuli and reduced ischemic brain damage in mice. Biotinylated compounds of NEPPs were synthesized to investigate their cellular accumulation. NEPP6-biotin protected the cells and emitted potent signals from the cells. In contrast, biotinylated non-neuroprotective derivatives emitted much weaker signals. These results suggest that NEPPs are novel types of neurotrophic compounds characterized by their dual biological activities of promoting neurite outgrowth and preventing neuronal death and that their accumulation in the cells is closely associated with their neuroprotective actions.

Topics: Animals; Biotin; Brain Ischemia; Cell Survival; Cells, Cultured; Cyclopentanes; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Mice; Microinjections; Nerve Growth Factors; Neurites; Neurons; Neuroprotective Agents; Prostaglandin D2; Prostaglandins; Structure-Activity Relationship

Focal ischemia was induced in the fronto-parietal region of rat brain, by injection of Rose Bengal, followed by light activation. Focal ischemia was accompanied by formation of PGD(2) peaking 60-90 min post irradiation and declining thereafter. Increased Cycloxygenase-2 (COX-2) expression was also observed. Control ischemic rats showed distinct morphological alterations with necrosis of neurons, glial cells and blood vessels, surrounded by a halo with pyknotic cells with cytoplasm swelling and vacuolization. Compound SC58236, a selective COX-2 inhibitor, dose-dependently prevented, ischemia-induced eicosanoid formation (area under the curve (AUC) of controls: 3.11 +/- 0.87; AUC of 20 mg/kg SC58236: 0.39 +/- 0.24), and caused significant reduction of damaged area (30.7 and 18.9% at SC58236 20 and 6.6 mg/kg), suggesting that selective inhibitors of COX-2 are neuroprotective.

Topics: Animals; Brain Ischemia; Cerebral Cortex; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Dose-Response Relationship, Drug; Fluorescent Dyes; Isoenzymes; Male; Microdialysis; Microscopy, Electron; Necrosis; Nerve Degeneration; Neurons; Neuroprotective Agents; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Wistar; Rose Bengal; Sulfonamides

Experiments compared the hemispheric neural damage resulting from global hemispheric hypoxic ischemia (GHHI, ligation of right common carotid artery plus 35 min of 12% O2) in groups of anesthetized, male Long Evans rats, 9-10 weeks of age, kept at 37 degrees C, and previously given an intracerebroventricular (i.c.v., 2.5 microl) injection of 28 or 70 pmoles of PGE2, PGF2alpha or PGD2 or sterile saline (SS) 30 min beforehand. Mean arterial pressure (MAP), ipsilateral cortical capillary blood flow (CBF), colonic (Tc), ipsilateral (Tipsi) and contralateral (Tcontra), temporalis muscle temperatures were measured before, during and for 15 min after GHHI. Necrotic neural damage was assessed 7 days post-GHHI. All groups given GHHI + PGs showed increased ipsilateral hemispheric damage to GHHI especially due to enhanced neocortical damage, compared to the saline control group given the same insult. PGD2 was the most potent PG to cause further damage to the global insult. Tc, Tipsi, Tcontra and MAP increased following the i.c.v. injection of PGE2. I.c.v. PGF2alpha transiently decreased MAP, PGD2 tended to decrease cerebral blood flow and neither evoked changes in temperature compared to respective pre-injection control values. Results demonstrate increased neural damage to GHHI with prior i.c.v. PGE2, PGF2alpha or PGD2 administration.

Topics: Animals; Body Temperature; Brain; Brain Ischemia; Dinoprost; Dinoprostone; Fever; Hemodynamics; Hypoxia, Brain; Male; Prostaglandin D2; Rats

Leukotrienes C4 and D4 are arachidonic acid metabolites that constrict blood vessels and enhance vascular permeability; their biosynthesis is initiated by the reaction of arachidonic acid with 5-lipoxygenase enzyme. After bilateral carotid artery occlusion for 15 minutes and reperfusion of the gerbil brain for 15 minutes, we determined the brain tissue concentrations of leukotrienes C4 and D4 by radioimmunoassay; they had increased from a baseline concentration of less than 1 to a mean +/- SEM concentration of 12.8 +/- 3.9 pmol/g brain. We also studied the effect of a flavonoid 5-lipoxygenase inhibitor on leukotriene production in the reperfused gerbil brain. A water-soluble flavonoid (5-hexyloxy-3',4'-dihydroxy-6,7-dimethoxyflavone 4'-disodium phosphate) was administered intravenously at a dose of 200 mg/kg body wt; 15 minutes later, both carotid arteries were occluded. The enhanced production of leukotrienes C4 and D4 in the reperfused brain was reduced by approximately 80% (from a mean +/- SEM of 12.8 +/- 3.9 to 2.2 +/- 1.3 pmol/g brain) in the presence of the 5-lipoxygenase inhibitor. The flavonoid did not affect the production of prostaglandin D2, the concentration of which also increased in the reperfused ischemic brain.

Topics: Animals; Arachidonate Lipoxygenases; Brain Ischemia; Chemical Phenomena; Chemistry; Flavonoids; Gerbillinae; Leukotriene Antagonists; Leukotrienes; Lipoxygenase Inhibitors; Prostaglandin D2; Radioimmunoassay; Reperfusion; SRS-A

The mean +/- SEM concentrations of immunoreactive leukotriene C4 and D4 (iLTD4) and prostaglandin D2 (iPGD2) increased from 3.0 +/- 1.2 and 0.71 +/- 0.33 to 16.3 +/- 4.7 and 3.0 +/- 1.14 ng/g forebrain, respectively (p less than 0.05, iLTD4; p less than 0.01, iPGD2), in the forebrains of 12 gerbils after 15 minutes of bilateral common carotid artery occlusion and 15 minutes of reperfusion. Removal of blood from ischemic brain of 11 gerbils by intracardiac perfusion with ice-cold saline for 10 minutes decreased iLTD4 concentrations significantly to 7.0 +/- 0.9 (p less than 0.05) but did not change iPGD2 concentrations. Severe granulocytopenia (4.98 +/- 1.79 to 0.05 +/- 0.03 x 10(3)/mm3, p less than 0.01) in seven gerbils following intraperitoneal injection of 50 mg/kg busulfan was associated with decreased iLTD4 accumulation in the brain to 3.46 +/- 1.36 ng/g forebrain (p less than 0.01). Taken together, our results suggest that blood components (most likely leukocytes) are a source of leukotriene-like immunoreactivity in the ischemic and reperfused brain.

Topics: Agranulocytosis; Animals; Blood Cells; Brain; Brain Ischemia; Busulfan; Gerbillinae; Leukocyte Count; Leukotrienes; Male; Platelet Count; Prostaglandin D2; Radioimmunoassay; Reperfusion