prostaglandin-d2 and Stroke

To meet the new challenges of modern lifestyles, we often compromise a good night's sleep. In preclinical models as well as in humans, a chronic lack of sleep is reported to be among the leading causes of various physiologic, psychologic, and neurocognitive deficits. Thus far, various endogenous mediators have been implicated in inter-regulatory networks that collectively influence the sleep-wake cycle. One such mediator is the lipocalin-type prostaglandin D2 synthase (L-PGDS)-Prostaglandin D2 (PGD2)-DP1 receptor (L-PGDS-PGD2-DP1R) axis. Findings in preclinical models confirm that DP1R are predominantly expressed in the sleep-regulating centers. This finding led to the discovery that the L-PGDS-PGD2-DP1R axis is involved in sleep regulation. Furthermore, we showed that the L-PGDS-PGD2-DP1R axis is beneficial in protecting the brain from ischemic stroke. Protein sequence homology was also performed, and it was found that L-PGDS and DP1R share a high degree of homology between humans and rodents. Based on the preclinical and clinical data thus far pertaining to the role of the L-PGDS-PGD2-DP1R axis in sleep regulation and neurologic conditions, there is optimism that this axis may have a high translational potential in human therapeutics. Therefore, here the focus is to review the regulation of the homeostatic component of the sleep process with a special focus on the L-PGDS-PGD2-DP1R axis and the consequences of sleep deprivation on health outcomes. Furthermore, we discuss whether the pharmacological regulation of this axis could represent a tool to prevent sleep disturbances and potentially improve outcomes, especially in patients with acute brain injuries.

Topics: Amino Acid Sequence; Animals; Brain; Humans; Intramolecular Oxidoreductases; Lipocalins; Male; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Sleep; Stroke

Cyclooxygenase (COX) enzymes catalyse the biotransformation of arachidonic acid to prostaglandins which subserve important functions in cardiovascular homeostasis. Prostacyclin (PGI2) and prostaglandin (PG)E2, dominant products of COX activityin macro- and microvascular endothelial cells, respectively, in vitro, modulate the interaction of blood cells with the vasculature and contribute to the regulation of blood pressure. COXs are the target for inhibition by nonsteroidal anti-inflammatory drugs (NSAIDs--which include those selective for COX-2) and for aspirin. Modulation of the interaction between COX products of the vasculature and platelets underlies both the cardioprotection afforded by aspirin and the cardiovascular hazard which characterises specific inhibitors of COX-2.

Topics: Animals; Cyclooxygenase 2 Inhibitors; Eicosanoids; Endothelium, Vascular; Epoprostenol; Gastrointestinal Hemorrhage; Heart Diseases; Humans; Isomerases; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Receptors, Epoprostenol; Receptors, Prostaglandin; Receptors, Thromboxane A2, Prostaglandin H2; Stroke; Thromboxane A2

Few clinically effective approaches reduce CNS-white matter injury. After early in-vivo white matter infarct, NFκB-driven pro-inflammatory signals can amplify a relatively small amount of vascular damage, resulting in progressive endothelial dysfunction to create a severe ischemic lesion. This process can be minimized by 15-deoxy-Δ(12,14)-prostaglandin J2 (PGJ(2)), an analog of the metabolically active PGD(2) metabolite. We evaluated PGJ(2)'s effects and mechanisms using rodent anterior ischemic optic neuropathy (rAION); an in vivo white matter ischemia model. PGJ(2) administration systemically administered either acutely or 5 hours post-insult results in significant neuroprotection, with stereologic evaluation showing improved neuronal survival 30 days post-infarct. Quantitative capillary vascular analysis reveals that PGJ(2) improves perfusion at 1 day post-infarct by reducing tissue edema. Our results suggest that PGJ(2) acts by reducing NFκB signaling through preventing p65 nuclear localization and inhibiting inflammatory gene expression. Importantly, PGJ(2) showed no in vivo toxicity structurally as measured by optic nerve (ON) myelin thickness, functionally by ON-compound action potentials, on a cellular basis by oligodendrocyte precursor survival or changes in ON-myelin gene expression. PGJ(2) may be a clinically useful neuroprotective agent for ON and other CNS infarcts involving white matter, with mechanisms of action enabling effective treatment beyond the currently considered maximal time for intervention.

Topics: Animals; Brain; Capillaries; Cerebral Infarction; Edema; Male; Neuroprotective Agents; NF-kappa B; Optic Nerve; Optic Neuropathy, Ischemic; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Signal Transduction; Stroke; Time Factors

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

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

Inducible cyclooxygenase (COX-2) catalyzes the first step in prostanoid biosynthesis and is considered a proinflammatory enzyme. COX-2 and type 1 inducible PGE synthase (mPGES-1) have a role in metalloproteinase (MMP) release leading to plaque rupture. In contrast, lipocalin-type PGD synthase (L-PGDS) has been shown to exert antiinflammatory actions. Thus, in this study we investigated whether a shift from a PGDS-oriented to a PGES-oriented profile in arachidonate metabolism leads to inflammatory activation in rupture-prone plaque macrophages.. Atherosclerotic plaques were obtained from 60 patients who underwent carotid endarterectomy, symptomatic (n=30) and asymptomatic (n=30) according to evidence of recent transient ischemic attack or stroke. Plaques were analyzed for COX-2, mPGES-1, L-PGDS, PPARgamma, IkappaBalpha, NF-kappaB, and MMP-9 by immunocytochemistry, Western blot, reverse-transcriptase polymerase chain reaction, enzyme immunoassay, and zymography. Prostaglandin E2 (PGE2) pathway was significantly prevalent in symptomatic plaques, whereas PGD2 pathway was overexpressed in asymptomatic ones, associated with NF-kappaB inactivation and MMP-9 suppression. In vitro COX-2 inhibition in monocytes was associated with reduced MMP-9 release only when PGD2 pathway overcame PGE2 pathway.. These results suggest that COX-2 may have proinflammatory and antiinflammatory properties as a function of expression of downstream PGH2 isomerases, and that the switch from L-PGDS to mPGES-1 in plaque macrophages is associated with cerebral ischemic syndromes, possibly through MMP-induced plaque rupture.

Topics: Arachidonic Acid; Carotid Artery Diseases; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Humans; I-kappa B Proteins; Inflammation; Intramolecular Oxidoreductases; Ischemic Attack, Transient; Isoenzymes; Lipocalins; Macrophages; Matrix Metalloproteinase 9; Membrane Proteins; NF-kappa B; NF-KappaB Inhibitor alpha; PPAR gamma; Prostaglandin D2; Prostaglandin-E Synthases; Prostaglandin-Endoperoxide Synthases; Stroke