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  • Ovid Technologies (Wolters Kluwer Health)  (5)
  • Bazan, Nicolas G  (5)
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  • Ovid Technologies (Wolters Kluwer Health)  (5)
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  • 1
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 51, No. Suppl_1 ( 2020-02)
    Abstract: Objectives: Ischemic stroke triggers a pattern of cellular and molecular disturbances that include lipid peroxidation, uncompensated oxidative stress, and neuronal injury. Recently, we have uncovered and characterized a novel neuroprotective signaling mechanism, which involves the activation of the biosynthesis of a family of lipid mediators in the brain made from omega-3 very-long-chain polyunsaturated fatty acids, that we named Elovanoids (ELVs). The present study evaluated ELVs, made of 32 and 34 C atoms in length (ELV-N32 and ELV-N34) and their potential mechanisms of action in cerebral ischemia. Methods: Male Sprague-Dawley rats were subjected to 2 h of middle cerebral artery occlusion (MCAo). Sodium salts (Na) or methyl esters (Me) ELVs were dissolved in artificial CSF and administered into right lateral ventricle at 3 h after onset of stroke. There were five groups: ELV-N32-Na, ELV-N32-Me, ELV-N34-Na, ELV-N34-Me (5μg/50μl), and CSF (50μl). Neurological function was evaluated on days 1, 3, and 7 after MCAo. Ex vivo MRI and immunohistochemistry were conducted on day 7. Results: All ELV treatments greatly improved neurologic scores in a sustained fashion up to the 7-day survival period. Ischemic core and penumbra volumes (computed from T2WI) were significantly reduced by all ELV treatments, and total lesion volumes were significantly reduced by ELV-N32-Na, ELV-N32-Me, ELV-N34-Na, and ELV-N34-Me compared to CSF-treated group (by 60%, 56%, 99%, and 91%, respectively). ELV-treated rats showed less infarction with an increased number of NeuN- and GFAP-positive cells as well as SMI-71-positive vessels in the cortex and less IgG staining in the cortex. ELV-mediated protection was extensive in the frontal-parietal cortex (tissue was salvaged by 57-96%), subcortex (73-75%), and total infarct volume, correction for brain swelling was dramatically reduced in all ELV-treated groups by 55-91%. Conclusion: We have shown that the administration of ELVs provides high-grade neurobehavioral recovery, decreases ischemic core and penumbra volumes, as well as attenuates cellular damage, blood vessel integrity, and BBB disruption.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2020
    detail.hit.zdb_id: 1467823-8
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  • 2
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 51, No. Suppl_1 ( 2020-02)
    Abstract: Objective: Ischemic injury induces neurogenesis in the subventricular zone (SVZ) of the lateral ventricles and subgranular zone (SGZ) of dentate gyrus (DG) promotes the migration of neuroblasts, guided by blood vessels, into the ischemic damaged area. Neurogenesis leads the functional and histological recovery in the ischemic-damaged brain through the proliferation, migration, differentiation and integration of newly generated neural cells into the existing neural circuit. Recently, we have shown that Docosahexaenoic acid (DHA) and Neuroprotectin D1 (NPD1) therapy improves functional and histological outcomes following experimental stroke. It has also been shown that DHA promotes neurite outgrowth of immature neurons, such as embryonic hippocampal cells and embryonic cortical cells. The objective of this study was to explore underlying mechanisms of docosanoid neuroprotection after cerebral ischemia. Methods: Male Sprague-Dawley rats were anesthetized with isoflurane/nitrous oxide, underwent 2h of middle cerebral artery occlusion (MCAo) and treated with DHA (5mg/kg, IV) or NPD1 (5μg/per rat, ICV) and vehicles 1h after. Neuro-behavioral assessments were conducted on days 1, 2, 3 and on weeks 1, 2, 3 or 4. BrdU was injected on days 4, 5 and 6, immunohistochemistry was performed on week 2 or 4, MRI on day 7 and lipidomic analysis at 4 and 5h after onset of stroke. Results: DHA improved short- and long-term behavioral functions and reduced cortical, subcortical and total infarct volumes (by 42%, 47% and 31%, respectively) after 2 weeks and reduced tissue loss by 50% after 4 weeks. DHA increased the number of BrdU + /Ki-67 + , BrdU + /DCX + and BrdU + /NeuN + cells in the cortex, subventricular zone and dentate gyrus and potentiated NPD1 synthesis in the penumbra at 5h after MCAo. NPD1 improved behavior, reduced lesion volumes, protected ischemic penumbra, increased NeuN, GFAP, SMI-71 positive cells and vessels, axonal regeneration in the penumbra and attenuated blood-brain barrier (BBB) after MCAo. Conclusion: We conclude that docosanoid administration increases neurogenesis, angiogenesis, activates NPD1 synthesis in the penumbra and diminishes BBB, which correlates to long-term neurobehavioral recovery after experimental ischemic stroke.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2020
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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  • 3
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 44, No. suppl_1 ( 2013-02)
    Abstract: INTRODUCTION: Docosahexaenoic acid (DHA; 22:6n-3) is an omega-3 essential fatty acid family member and the precursor of neuroprotectin D1, a lipid mediator which downregulates apoptosis and promotes cell survival. Recently, we have shown that DHA therapy improves functional and histological outcomes following experimental stroke. We examined the effect of DHA on blood-brain barrier (BBB) integrity after middle cerebral artery occlusion (MCAo) in rats. Damage to the BBB was judged by extravasation of Evans Blue (EB) dye. METHODS: Male SD rats were anesthetized with isoflurane and subjected to 2 h of MCAo by retrograde insertion of an intraluminal suture. DHA (5 mg/kg) or vehicle (saline) was administered IV at 3 h after the onset of MCAo and animals were sacrificed at 6, 24 or 72 h. Behavioral tests were performed at 5, 24, 48 or 72 h. EB (2% in saline, 4 ml/kg) was administered IV either at 5, 23 or 71 h after onset of MCAo. Fluorometric quantitation of EB was performed 1 h later in six brain regions. RESULTS: Physiological variables were stable and showed no significant differences between groups. In the 6 h series (n=9 per group), DHA decreased EB extravasation in the posterior ischemic hemisphere compared to saline (9.2±1.1 vs. 14.3± 1.5, respectively). In the 24 h series (n=8-9 per group), DHA improved behavioral scores on day 1 and decreased EB extravasation in the posterior ischemic hemisphere (4.9±0.41 vs. 8.5±1.0) and cortical area (3.0±0.4 vs. 8.6± 2.0, respectively) compared to saline. In the 72 h series (n=12 per group), DHA improved behavioral scores on days 1, 2 and 3, and decreased EB extravasation in the anterior (6.1±0.8 vs. 9.6±0.9), posterior (5.6±0.7 vs. 9.1±1.2, respectively) ischemic hemispheres compared to saline. In addition, EB extravasation was decreased by DHA in the cortical area (6.2±1.0 vs. 10.1±1.1) and total hemisphere (11.7±1.3 vs. 18.7±1.9, respectively) compared to vehicle. CONCLUSION: These data have demonstrated that DHA is an effective neuroprotective drug, diminishing BBB damage in a model of severe focal ischemia. Thus, it is reasonable to hypothesize that DHA may have potential use in treating focal ischemic stroke in the clinical setting. This study was supported by NIH, NINDS grant R01 NS065786 (LB) and R01 NS046741 (NGB).
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2013
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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  • 4
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 53, No. Suppl_1 ( 2022-02)
    Abstract: Objective: Ischemic stroke induces multiple pathophysiological processes involving oxidative stress, loss of homeostasis, excitotoxicity, disruption of the blood-brain barrier and neurovascular unit, contributing to neuronal death. In the early phases following the onset of ischemic damage, neuroinflammation contributes to tissue damage and enlargement of the infarct area. Elovanoids (ELVs) are a class of pro-homeostatic lipid mediators that are derivatives of very long-chain polyunsaturated fatty acids (VLC-PUFAs). VLC-PUFAs are synthesized by ELOVL4 an enzyme primarily expressed in neurons. ELVs have been shown to reduce infarct volume and promote cell survival when administered IV following 2h of middle cerebral artery occlusion (MCAo). This study aimed to test the neuroprotective efficacy of these VLC-PUFA ELV precursors when administered intranasally (IN) in a model of experimental ischemic stroke. Methods: Male Sprague-Dawley rats received 2h of the middle cerebral artery occlusion (MCAo). Treatment with C-36:6, C-38:6 (1μg/μl, 20 μg) or vehicle (saline + ethanol) was administered at 1, 24, and 48h after onset MCAo. Behavior was evaluated using a composite neurological battery; a grading scale of 0-12 was employed (normal score=0, maximal deficit=12). Behavior testing was performed on days 1, 2, 3, and 7, followed by ex vivo MRI for lesion volumes and edema (T2WI) and immunohistochemistry on day 7. Results: Following drug administration, no behavioral side effects were observed. Neurologic function was improved on days 1, 3, and 7 by 24%, 37%, and 28% in animals receiving C-36:6 and by 26%, 26%, and 29% in the group receiving C-38:6. Total, core, and penumbra lesion volumes, computed using T2WI, were reduced with C-36:6 by 60%, 68%, and 53%, and C-38:6 by 35%, 43% 25% vs vehicle. Total, cortical and subcortical infarct areas and volumes were reduced by treatments with C-36:6 (by 42% 48% and 34%) and C-38:6 (by 28% 31% and 20%) vs vehicle. Conclusion: IN delivered ELV precursors demonstrated neuroprotective efficacy improving behavior and reducing infarct volume compared to vehicle. We are exploring neuroprotective molecular mechanisms exerted by intranasally delivered VLC-PUFAs as an experimental therapeutic approach.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2022
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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  • 5
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 43, No. suppl_1 ( 2012-02)
    Abstract: Background and Purpose: Acute ischemic stroke triggers complex neurovascular, neuroinflammatory and synaptic alterations. Aspirin and the omega-3 essential fatty acid, docosahexaenoic acid (DHA), have beneficial effects on cerebrovascular diseases. Unlike most anti-inflammatory agents, aspirin jumpstarts resolution mainly due to acetylation of cyclooxygenase enzymes. Both neuroprotectin D1 (NPD1) and its precursor, DHA, participate in neuroprotection. Here we have tested the effect of aspirin plus DHA administration and discovered the synthesis of aspirin-triggered NPD1 (AT-NPD1) in the penumbra. Then we performed the total chemical synthesis of this molecule and, upon systemic administration 1h after 2h of middle cerebral artery occlusion (MCAo), uncovered remarkable protection. Methods: Sprague-Dawley rats were anesthetized with isoflurane and received 2h MCAo. Neurological status was evaluated at 24h, 48h, 72h, and 7 days. Treatment with 333µg/kg of AT-NPD1 sodium salt (AT-NPD1-SS) or AT-NPD1 methyl-ester (AT-NPD1-ME) or vehicle (saline) (n=7-8 per group) was administered i.v. at 3h after stroke. On day 7, ex vivo magnetic resonance imaging (MRI) of the brains was conducted on 11.7T MRI. T2WI, 3D volumes, and apparent diffusion coefficient (ADC) maps were generated. In addition, infarct volumes and number of GFAP (reactive astrocytes), ED-1 (activated microglia/microphages) and NeuN (neurons)-positive cells were counted in the cortex and striatum at the level of the central lesion. Results: All animals showed similar values for rectal and cranial temperatures, arterial blood gases, and plasma glucose during and after MCAo. Treatment with both AT-NPD1-SS and AT-NPD1-ME significantly improved neurological scores compared to saline treatment at 24h, 48h, 72h and 7 days. Total lesion volumes computed from T2WI images were significantly reduced by both AT-NPD1-SS and AT-NPD1-ME treatment in the cortex (by 44% and 81%, respectively), striatum (by 61% and 77%) and total infarct (by 48% and 78%, respectively). Brain edema, computed from T2WI in the cortex (penumbra) and striatum (core), was elevated in the saline group. In contrast, both AT-NPD1-SS and AT-NPD1-ME decreased water content in the striatum on day 7. 3D volumes, computed from T2WI, were dramatically reduced with AT-NPD1-SS and AT-NPD1-ME, and the lesion was mostly localized in the subcortical areas. Treatment with both AT-NPD1-SS and AT-NPD1-ME significantly reduced cortical (by 76% and 96%), subcortical (by 61% and 70%) and total (69% and 84%) infarct volumes as defined by histopathology. Conclusions: Ex vivo MRI, histopathology, and behavioral testing shows neuroprotective efficacy of novel AT-NPD1 therapy in focal cerebral ischemia and uncover a novel approach for pharmaceutical intervention and clinical translation.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2012
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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