Dataset Information

Targeting resolution of neuroinflammation after ischemic stroke with a lipoxin A4 analog: Protective mechanisms and long-term effects on neurological recovery.

ABSTRACT: BACKGROUND:Resolution of inflammation is an emerging new strategy to reduce damage following ischemic stroke. Lipoxin A4 (LXA 4) is an anti-inflammatory, pro-resolution lipid mediator that reduces neuroinflammation in stroke. Since LXA 4 is rapidly inactivated, potent analogs have been synthesized, including BML-111. We hypothesized that post-ischemic, intravenous treatment with BML-111 for 1 week would provide neuroprotection and reduce neurobehavioral deficits at 4 weeks after ischemic stroke in rats. Additionally, we investigated the potential protective mechanisms of BML-111 on the post-stroke molecular and cellular profile. METHODS:A total of 133 male Sprague-Dawley rats were subjected to 90 min of transient middle cerebral artery occlusion (MCAO) and BML-111 administration was started at the time of reperfusion. Two methods of week-long BML-111 intravenous administration were tested: continuous infusion via ALZET ® osmotic pumps (1.25 and 3.75 ?g ?l-1 hr-1), or freshly prepared daily single injections (0.3, 1, and 3 mg/kg). We report for the first time on the stability of BML-111 and characterized an optimal dose and a dosing schedule for the administration of BML-111. RESULTS:One week of BML-111 intravenous injections did not reduce infarct size or improve behavioral deficits 4 weeks after ischemic stroke. However, post-ischemic treatment with BML-111 did elicit early protective effects as demonstrated by a significant reduction in infarct volume and improved sensorimotor function at 1 week after stroke. This protection was associated with reduced pro-inflammatory cytokine and chemokine levels, decreased M1 CD40+ macrophages, and increased alternatively activated, anti-inflammatory M2 microglia/macrophage cell populations in the post-ischemic brain. CONCLUSION:These data suggest that targeting the endogenous LXA 4 pathway could be a promising therapeutic strategy for the treatment of ischemic stroke. More work is necessary to determine whether a different dosing regimen or more stable LXA 4 analogs could confer long-term protection.

SUBMITTER: Hawkins KE

PROVIDER: S-EPMC5434193 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Targeting resolution of neuroinflammation after ischemic stroke with a lipoxin A<sub>4</sub> analog: Protective mechanisms and long-term effects on neurological recovery.

Hawkins Kimberly E KE DeMars Kelly M KM Alexander Jon C JC de Leon Lauren G LG Pacheco Sean C SC Graves Christina C Yang Changjun C McCrea Austin O AO Frankowski Jan C JC Garrett Timothy J TJ Febo Marcelo M Candelario-Jalil Eduardo E

Brain and behavior 20170412 5

<h4>Background</h4>Resolution of inflammation is an emerging new strategy to reduce damage following ischemic stroke. Lipoxin A<sub>4</sub> (LXA <sub>4</sub>) is an anti-inflammatory, pro-resolution lipid mediator that reduces neuroinflammation in stroke. Since LXA <sub>4</sub> is rapidly inactivated, potent analogs have been synthesized, including BML-111. We hypothesized that post-ischemic, intravenous treatment with BML-111 for 1 week would provide neuroprotection and reduce neurobehavioral d ...[more]

PMID: 28523230

Similar Datasets

Project description:BACKGROUND AND PURPOSE:Targeting the prostaglandin I2 prostanoid (IP) receptor to reduce stroke injury has been hindered by the lack of selective drugs. MRE-269 is the active metabolite of selexipag showing a high selectivity toward the IP receptor. Selexipag has been recently approved for clinical use in pulmonary hypertension. We hypothesized that postischemic treatment with MRE-269 provides long-lasting neuroprotection with improved neurological outcomes in a clinically relevant rat stroke model. METHODS:Aged male Sprague-Dawley rats underwent transient middle cerebral artery occlusion and were randomly selected to receive either vehicle or MRE-269 (0.25 mg/kg) intravenously starting at 4.5 hours post ischemia. Accelerating rotarod and adhesive removal tests were conducted before and at 3, 7, 14, and 21 days after stroke. Infarct volume was quantified by magnetic resonance imaging at 48 hours and 21 days post middle cerebral artery occlusion. In parallel experiments, cerebral cortex samples from stroke and nonstroke sides from vehicle- and MRE-269-treated groups were collected at 18 hours post middle cerebral artery occlusion for molecular biology analyses. RESULTS:Quantitative magnetic resonance imaging data showed that postischemic MRE-269 treatment significantly reduced infarct volume compared with vehicle-treated rats at both 48 hours and 3 weeks after stroke. MRE-269 treatment resulted in a significant long-term recovery in both locomotor and somatosensory functions after middle cerebral artery occlusion, which was associated with a reduced weight loss in animals receiving the IP receptor agonist. Postischemic MRE-269 treatment reduced proinflammatory cytokines/chemokines and oxidative stress. Damage to the blood-brain barrier, as assessed by extravasation of immunoglobulin G to the ischemic brain, was significantly reduced by MRE-269, which was associated with a reduction in matrix metalloproteinase-9 activity in the brain of stroked aged rats given the IP agonist at 4.5 hours after ischemia onset. CONCLUSIONS:Our data suggest that targeting the IP receptor with MRE-269 is a novel strategy to reduce cerebral ischemia injury and promote long-term neurological recovery in ischemic stroke.

Project description:Background:Improving our knowledge about the impact of restorative therapies employed in the rehabilitation of a stroke patient may help guide practitioners in prescribing treatment regimen that may lead to better post-stroke recovery and quality of life. Aims:To evaluate the neurological and functional recovery for 3 months after an acute ischemic stroke occurred within previous 3 months. To determine predictors of recovery. Design:Prospective observational registry. Population. Patients having suffered acute moderate to severe ischemic stroke of moderate to severe intensity within the previous 3 months with National Institutes of Health Stroke Scale (NIHSS) score from 10 to 20, 24 hours after arrival at emergency room (ER). Methods:All prespecified variables (sociodemographic and clinical data, lifestyle recommendations, rehabilitation prescription, and neurological assessments) were assessed at three visits, i.e., baseline (D0), one month (M1), and three months (M3). Results:Out of 143 recruited patients, 131 could be analysed at study entry within 3 months after stroke onset with a mean acute NIHSS score of 14.05, decreased to 10.8 at study baseline. Study sample was aged 64.9 ± 13.8?years, with 49.2% of women. Neurorehabilitation treatment was applied to 9 of 10 patients from the acute phase and for three months with different intensities depending on the centre. A large proportion of patients recovered from severe dependency on activities of daily living (ADL) at D0 to a mild or moderate disability requiring some help at M3: mean NIHSS = 10.8?to?5.7; median?modified?Rankin?Scale?(mRS) = 4?to?3; Barthel?index?(BI) = 40?to?70; all p?values < 0.001. Multivariate analyses integrating other regression variables showed a trend in favour of rehabilitation and revascularization therapies on recovery although did not reach statistical significance and that the positive predictors of recovery improvement were baseline BI score, time to treatment, and dietary supplement MLC901 (NurAiD™II). A larger percentage of patients with more severe stroke (NIHSS > 14) who received MLC901 showed above median improvements on mRS compared to control group at M1 (71.4% vs. 29.4%; p = 0.032) and M3 (85.7% vs. 50%; p = 0.058). Older subjects and women tend to have less improvement by M3. Conclusions:Our study in patients with moderate to severe stroke shows overall recovery on neurological and functional assessments during the 3 months of study observation. Apart from demonstrating traditional "non-modifiable" predictors of outcome after stroke, like age, sex, and stroke severity, we also detected association between the use of dietary supplement MLC901 and recovery.

Project description:BACKGROUND:Ischemic stroke results in a robust inflammatory response within the central nervous system. As the immune-inhibitory CD200-CD200 receptor 1 (CD200R1) signaling axis is a known regulator of immune homeostasis, we hypothesized that it may play a role in post-stroke immune suppression after stroke. METHODS:In this study, we investigated the role of CD200R1-mediated signaling in stroke using CD200 receptor 1-deficient mice. Mice were subjected to a 60-min middle cerebral artery occlusion and evaluated at days 3 and 7, representing the respective peak and early resolution stages of neuroinflammation in this model of ischemic stroke. Infarct size and behavioral deficits were assessed at both time points. Central and peripheral cellular immune responses were measured using flow cytometry. Bacterial colonization was determined in lung tissue homogenates both after acute stroke and in an LPS model of systemic inflammation. RESULTS:In wild-type (WT) animals, CD200R1 was expressed on infiltrating monocytes and lymphocytes after stroke but was absent on microglia. Early after ischemia (72?h), CD200R1-knockout (KO) mice had significantly poorer survival rates and an enhanced susceptibility to spontaneous bacterial colonization of the respiratory tract compared to wild-type (WT) controls, despite no difference in infarct or neurological deficits. While the CNS inflammation was resolved by day 7 post-stroke in WT mice, brain-resident microglia and monocyte activation persisted in CD200R1-KO mice, accompanied by a delayed, augmented lymphocyte response. At this time point, CD200R1-KO mice displayed greater weight loss, more severe neurological deficits, and impaired motor function compared to WT. Systemically, CD200R1-KO mice exhibited signs of persistent infection including lymphopenia, T cell activation and memory conversion, and narrowing of the TCR repertoire. These findings were confirmed in a second model of acute neuroinflammation induced by systemic endotoxin challenge. CONCLUSION:This study defines an essential role of CD200-CD200R1 signaling in stroke. Loss of CD200R1 led to high mortality, increased rates of post-stroke infection, and enhanced entry of peripheral leukocytes into the brain after ischemia, with no increase in infarct size. This suggests that the loss of CD200 receptor leads to enhanced peripheral inflammation that is triggered by brain injury.

Dataset Information

Targeting resolution of neuroinflammation after ischemic stroke with a lipoxin A4 analog: Protective mechanisms and long-term effects on neurological recovery.

Publications

Targeting resolution of neuroinflammation after ischemic stroke with a lipoxin A<sub>4</sub> analog: Protective mechanisms and long-term effects on neurological recovery.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets