scholarly journals Cellular and Molecular Mechanisms of R/S-Roscovitine and CDKs Related Inhibition under Both Focal and Global Cerebral Ischemia: A Focus on Neurovascular Unit and Immune Cells

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 104
Author(s):  
Lucas Le Roy ◽  
Anne Letondor ◽  
Cloé Le Roux ◽  
Ahmed Amara ◽  
Serge Timsit
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Molecular Mechanisms ◽  
Focal Cerebral Ischemia ◽  
Neurovascular Unit ◽  
Brain Lesions ◽  
Global Cerebral Ischemia ◽  
Inflammatory Models ◽  
Long Time ◽  
Inflammatory Processes

Ischemic stroke is the second leading cause of death worldwide. Following ischemic stroke, Neurovascular Unit (NVU) inflammation and peripheral leucocytes infiltration are major contributors to the extension of brain lesions. For a long time restricted to neurons, the 10 past years have shown the emergence of an increasing number of studies focusing on the role of Cyclin-Dependent Kinases (CDKs) on the other cells of NVU, as well as on the leucocytes. The most widely used CDKs inhibitor, (R)-roscovitine, and its (S) isomer both decreased brain lesions in models of global and focal cerebral ischemia. We previously showed that (S)-roscovitine acted, at least, by modulating NVU response to ischemia. Interestingly, roscovitine was shown to decrease leucocytes-mediated inflammation in several inflammatory models. Specific inhibition of roscovitine majors target CDK 1, 2, 5, 7, and 9 showed that these CDKs played key roles in inflammatory processes of NVU cells and leucocytes after brain lesions, including ischemic stroke. The data summarized here support the investigation of roscovitine as a potential therapeutic agent for the treatment of ischemic stroke, and provide an overview of CDK 1, 2, 5, 7, and 9 functions in brain cells and leucocytes during cerebral ischemia.

scholarly journals Angiogenesis in the ischemic core: A potential treatment target?

2019 ◽  
Vol 39 (5) ◽  
pp. 753-769 ◽  
Author(s):  
Masato Kanazawa ◽  
Tetsuya Takahashi ◽  
Masanori Ishikawa ◽  
Osamu Onodera ◽  
Takayoshi Shimohata ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Tissue Injury ◽  
Focal Cerebral Ischemia ◽  
Neurovascular Unit ◽  
Focal Ischemia ◽  
Model Systems ◽  
Surrounding Tissue ◽  
Model Studies ◽  
Ischemic Core

The ischemic penumbra is both a concept in understanding the evolution of cerebral tissue injury outcome of focal ischemia and a potential therapeutic target for ischemic stroke. In this review, we examine the evidence that angiogenesis can contribute to beneficial outcomes following focal ischemia in model systems. Several studies have shown that, following cerebral ischemia, endothelial proliferation and subsequent angiogenesis can be detected beginning four days after cerebral ischemia in the border of the ischemic core, or in the ischemic periphery, in rodent and non-human primate models, although initial signals appear within hours of ischemia onset. Components of the neurovascular unit, its participation in new vessel formation, and the nature of the core and penumbra responses to experimental focal cerebral ischemia, are considered here. The potential co-localization of vascular remodeling and axonal outgrowth following focal cerebral ischemia based on the definition of tissue remodeling and the processes that follow ischemic stroke are also considered. The region of angiogenesis in the ischemic core and its surrounding tissue (ischemic periphery) may be a novel target for treatment. We summarize issues that are relevant to model studies of focal cerebral ischemia looking ahead to potential treatments.

scholarly journals Human-Albumin Neuroprotection in Acute Ischemic Stroke: Marked Efficacy at Moderate Doses, with a Broad Therapeutic Window.

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 326-326
Author(s):  
Myron D Ginsberg ◽  
Ludmila Belayev ◽  
Yitao Liu ◽  
Weizhao Zhao ◽  
Raul Busto
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Acute Ischemic Stroke ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Human Albumin ◽  
Global Cerebral Ischemia ◽  
Therapeutic Window ◽  
High Dose ◽  
Neurological Score

58 We have previously shown that high-dose human albumin (Alb) is markedly neuroprotective in focal and global cerebral ischemia and in traumatic brain injury. In this study, we examined the efficacy of moderate, clinically achievable Alb doses and defined the therapeutic window in focal cerebral ischemia. Sprague Dawley rats (n=62) were anesthetized with halothane/nitrous oxide and received 2-h middle cerebral artery occlusion (MCAo) by intraluminal suture. Neurological status was evaluated during occlusion (60 min) and daily for 3 days after MCAo. In the dose-response study, animals were given either 25% Alb in doses 0.63 or 1.25 g/kg , or 0.9% saline vehicle, i.v. immediately after suture removal (n=5 each). In the therapeutic window study, 1.25 g/kg Alb was administered at either 2 h, 3 h, 4 h, or 5 h after onset of stroke (i.e., 0 to 3 h after onset of reperfusion) (n=9–10 ea.). Three days after MCAo, brains were perfusion-fixed, and image-processing was used to compute infarct volumes and brain swelling. Both moderate Alb doses (0.63 and 1.25 g/kg) significantly improved the neurological score compared to vehicle rats at 24h, 48h and 72h; and markedly reduced cortical infarct volume (by 66±14% and 95±4%, respectively), striatal infarct volume (by 54±8% and 52±14%), and total infarct volume (by 58±5% and 67±9%, respectively). Brain edema was virtually eliminated by Alb treatment. In the therapeutic window study, even when treatment was initiated as late as 4 hours after onset of MCAo, 1.25 g/kg Alb led to significantly improved neurological score and highly significant reductions of infarct areas in cortex (68% reduction), subcortical regions (52% reduction), and total infarct (61% reduction). The striking efficacy and broad therapeutic window of moderate-dose Alb therapy in experimental focal ischemia strongly supports the feasibility of initiating early-phase clinical trials of this promising agent in patients with acute ischemic stroke. This work was supported by NIH Grant NS05820 (MDG) and by AHA Initial Investigator Award (LB).

scholarly journals Hypothermic neuroprotection against acute ischemic stroke: The 2019 update

2019 ◽  
Vol 40 (3) ◽  
pp. 461-481 ◽  
Author(s):  
Longfei Wu ◽  
Di Wu ◽  
Tuo Yang ◽  
Jin Xu ◽  
Jian Chen ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Acute Ischemic Stroke ◽  
Brain Injuries ◽  
Focal Cerebral Ischemia ◽  
Global Cerebral Ischemia ◽  
Neuroprotective Effects ◽  
Neuroprotective Strategies ◽  
Selective Cooling ◽  
Ischemic Encephalopathy

Acute ischemic stroke is a leading cause of death and disability worldwide. Therapeutic hypothermia has long been considered as one of the most robust neuroprotective strategies. Although the neuroprotective effects of hypothermia have only been confirmed in patients with global cerebral ischemia after cardiac arrest and in neonatal hypoxic ischemic encephalopathy, establishing standardized protocols and strictly controlling the key parameters may extend its application in other brain injuries, such as acute ischemic stroke. In this review, we discuss the potential neuroprotective effects of hypothermia, its drawbacks evidenced in previous studies, and its potential clinical application for acute ischemic stroke especially in the era of reperfusion. Based on the different conditions between bench and bedside settings, we demonstrate the importance of vascular recanalization for neuroprotection of hypothermia by analyzing numerous literatures regarding hypothermia in focal cerebral ischemia. Then, we make a thorough analysis of key parameters of hypothermia and introduce novel hypothermic therapies. We advocate in favor of the process of clinical translation of intra-arterial selective cooling infusion in the era of reperfusion and provide insights into the prospects of hypothermia in acute ischemic stroke.

scholarly journals Leukocyte-Endothelium Interactions during Permanent Focal Cerebral Ischemia in Mice

2004 ◽  
Vol 24 (6) ◽  
pp. 668-676 ◽  
Author(s):  
Hiroharu Kataoka ◽  
Seong-Woong Kim ◽  
Nikolaus Plesnila
Keyword(s):  
Cerebral Ischemia ◽  
Brain Damage ◽  
Molecular Mechanisms ◽  
Focal Cerebral Ischemia ◽  
Fluorescent Microscopy ◽  
Capillary Density ◽  
Artery Occlusion ◽  
Cerebral Artery Occlusion ◽  
Adherent Leukocytes

The contribution of leukocyte infiltration to brain damage after permanent focal cerebral ischemia and the underlying molecular mechanisms are still unclear. Therefore, the aim of this study was to establish a mouse model for the visualization of leukocytes in the cerebral microcirculation in vivo and to investigate leukocyte-endothelial interaction (LEI) after permanent middle cerebral artery occlusion (MCAO). Sham-operated 129/Sv mice showed physiologic LEI in pial venules as observed by intravital fluorescent microscopy. Permanent focal cerebral ischemia induced a significant increase of LEI predominantly in pial venules. The number of rolling and adherent leukocytes reached 36.5 ± 13.2/100 μm × min and 22.5 ± 7.9/100 μm × min, respectively at 120 minutes after MCAO ( P = 0.016 vs. control). Of note, rolling and adherent leukocytes were also observed in arterioles of ischemic animals (7.3 ± 3.0/100 μm × min rolling and 3.0 ± 3.6/100 μm × min adherent). Capillary density was not different between groups. These results demonstrate that leukocytes accumulate in the brain not only after transient but also after permanent focal cerebral ischemia and may therefore contribute to brain damage after stroke without reperfusion.

Matrix metalloproteinase-9 : surrogate marker and therapeutic target against neurovascular impairment after cerebral ischemia

2015 ◽  
Author(s):  
◽  
Shanyan Chen
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Molecular Mechanisms ◽  
Combined Treatment ◽  
Cell Penetrating Peptides ◽  
Therapeutic Window ◽  
Gelatinase Activity

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Stroke ranks fourth among all causes of death, and acute ischemic stroke is the most common form. The neurovascular unit (NVU) describes a basic functional structure in the brain and is primarily composed of endothelial cells, pericytes, astrocytes, microglia and neurons. The dynamic structure of the NVU is highly regulated due to interactions between different cells and extracellular matrix (ECM) components. Proteolysis of the ECM by matrix metalloproteinases (MMPs), especially MMP-9, plays an important role in the pathophysiology of cerebral ischemia and administration of tissue plasminogen activator (tPA). The activation of gelatinases (MMP-2/9) is considered a key mechanism involved in the impairment of NVU. The overall goal of this research project is to examine the role of MMP-9 in the neurovascular impairment after ischemic stroke in mice. In this project, we implemented a new strategy using gelatinase-activatable cell-penetrating peptides (ACPPs) tagged with fluorescence and/or gadolinium-based contrast agents to investigate proteolysis of gelatinases as surrogate markers of neurovascular integrity. We presented evidence that the combination of a sensitive fluorescent chromatophore and MRI contrast enhancement agent can be used to monitor gelatinase activity and its distribution in cultured neurons as well as in mice after focal cerebral ischemia. Detection of the activity of gelatinases in vivo using ACPPs could provide insights into the underlying mechanism for gelatinase proteolysis that mediate ischemia-related neurovascular impairment. We also applied a two-dimensional (2D) gelatin zymography technique that combines isoelectric focusing (IEF) with zymographic electrophoresis. We demonstrated that the 2D zymography approach can improve separation of different isoforms of gelatinases in both in vitro and in vivo conditions. 2D zymography is an effective method to separate posttranslational modification isoforms of gelatinases and to identify modifications that regulate their enzymatic activity in acute brain injuries. In work that follows, we used a fibrin-rich blood clot to occlude the middle cerebral artery (MCA) in mice as a model to represent the critical thromboembolic features of ischemic stroke in humans. In this study, we evaluated effects of SB-3CT, a mechanism-based inhibitor selective for gelatinases. We demonstrated MMP-9 activation and neurovasculature impairment in this stroke model, and showed the ability of SB-3CT to inhibit MMP-9 activity in vivo, which in turn resulted in maintenance of laminin, antagonism of pericyte contraction and loss, preservation of laminin-positive pericytes and endothelial cells, and thus rescuing neurons from apoptosis and preventing intracerebral hemorrhage. We further demonstrated that SB-3CT/tPA combined treatment could attenuate MMP-9 -- mediated degradation of endothelial laminin, impairment of endothelial cells, and decrease of caveolae -- mediated transcytosis. Early inhibition of MMP-9 proteolysis by SB-3CT decreased brain damage, reduced BBB disruption, and prevented hemorrhagic transformation after delayed tPA treatment. Therefore usage of SB-3CT will be helpful in accessing combination therapy with tPA in ischemic stroke. Results from these studies indicate the important role of MMP-9 in cerebral ischemia and thus the need for further studies to explore the molecular mechanisms underlying its activation and regulation. Results further demonstrated that the combined use of MMP-9 inhibitor with tPA may extend tPA therapeutic window for mitigating stroke damage.

scholarly journals Tissue Acidosis Associated with Ischemic Stroke to Guide Neuroprotective Drug Delivery

Biology ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 460
Author(s):  
Orsolya M. Tóth ◽  
Ákos Menyhárt ◽  
Rita Frank ◽  
Dóra Hantosi ◽  
Eszter Farkas ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Targeted Delivery ◽  
Focal Cerebral Ischemia ◽  
Ischemic Penumbra ◽  
Risk Of Injury ◽  
Ischemic Tissue ◽  
Tissue Acidosis ◽  
Injury Progression

Ischemic stroke is a leading cause of death and disability worldwide. Yet, the effective therapy of focal cerebral ischemia has been an unresolved challenge. We propose here that ischemic tissue acidosis, a sensitive metabolic indicator of injury progression in cerebral ischemia, can be harnessed for the targeted delivery of neuroprotective agents. Ischemic tissue acidosis, which represents the accumulation of lactic acid in malperfused brain tissue is significantly exacerbated by the recurrence of spreading depolarizations. Deepening acidosis itself activates specific ion channels to cause neurotoxic cellular Ca2+ accumulation and cytotoxic edema. These processes are thought to contribute to the loss of the ischemic penumbra. The unique metabolic status of the ischemic penumbra has been exploited to identify the penumbra zone with imaging tools. Importantly, acidosis in the ischemic penumbra may also be used to guide therapeutic intervention. Agents with neuroprotective promise are suggested here to be delivered selectively to the ischemic penumbra with pH-responsive smart nanosystems. The administered nanoparticels release their cargo in acidic tissue environment, which reliably delineates sites at risk of injury. Therefore, tissue pH-targeted drug delivery is expected to enrich sites of ongoing injury with the therapeutical agent, without the risk of unfavorable off-target effects.

scholarly journals Transcriptomic characterization of microglia activation in a rat model of ischemic stroke

2020 ◽  
Vol 40 (1_suppl) ◽  
pp. S34-S48
Author(s):  
Wenjun Deng ◽  
Emiri Mandeville ◽  
Yasukazu Terasaki ◽  
Wenlu Li ◽  
Julie Holder ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Phenotypic Diversity ◽  
Focal Cerebral Ischemia ◽  
Wide Spectrum ◽  
Spontaneously Hypertensive ◽  
Transient Focal Cerebral Ischemia ◽  
Microglial Response ◽  
Whole Transcriptome

Microglia are key regulators of inflammatory response after stroke and brain injury. To better understand activation of microglia as well as their phenotypic diversity after ischemic stroke, we profiled the transcriptome of microglia after 75 min transient focal cerebral ischemia in 3-month- and 12-month-old male spontaneously hypertensive rats. Microglia were isolated from the brains by FACS sorting on days 3 and 14 after cerebral ischemia. GeneChip Rat 1.0ST microarray was used to profile the whole transcriptome of sorted microglia. We identified an evolving and complex pattern of activation from 3 to 14 days after stroke onset. M2-like patterns were extensively and persistently upregulated over time. M1-like patterns were only mildly upregulated, mostly at day 14. Younger 3-month-old brains showed a larger microglial response in both pro- and anti-inflammatory pathways, compared to older 12-month-old brains. Importantly, our data revealed that after stroke, most microglia are activated towards a wide spectrum of novel polarization states beyond the standard M1/M2 dichotomy, especially in pathways related to TLR2 and dietary fatty acid signaling. Finally, classes of transcription factors that might potentially regulate microglial activation were identified. These findings should provide a comprehensive database for dissecting microglial mechanisms and pursuing neuroinflammation targets for acute ischemic stroke.

scholarly journals Catheter based selective hypothermia reduces stroke volume during focal cerebral ischemia in swine

2015 ◽  
Vol 8 (4) ◽  
pp. 418-422 ◽  
Author(s):  
Thomas K Mattingly ◽  
Lynn M Denning ◽  
Karen L Siroen ◽  
Barb Lehrbass ◽  
Pablo Lopez-Ojeda ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Stroke Volume ◽  
Acute Ischemic Stroke ◽  
Brain Mri ◽  
Global Cerebral Ischemia ◽  
Moderate Hypothermia ◽  
Stroke Model ◽  
Stroke Treatment ◽  
Endovascular Cooling

BackgroundTotal body hypothermia is an established neuroprotectant in global cerebral ischemia. The role of hypothermia in acute ischemic stroke remains uncertain. Selective application of hypothermia to a region of focal ischemia may provide similar protection with more rapid cooling and elimination of systemic side effects. We studied the effect of selective endovascular cooling in a focal stroke model in adult domestic swine.MethodsAfter craniotomy under general anesthesia, a proximal middle cerebral artery branch was occluded for 3 h, followed by 3 h of reperfusion. In half of the animals, selective hypothermia was induced during reperfusion using a dual lumen balloon occlusion catheter placed in the ipsilateral common carotid artery. Following reperfusion, the animals were sacrificed. Brain MRI and histology were evaluated by experts who were blinded to the intervention.Results25 animals were available for analysis. Using selective hypothermia, hemicranial temperature was successfully cooled to a mean of 26.5°C. Average time from start of perfusion to attainment of moderate hypothermia (<30°C) was 25 min. Mean MRI stroke volumes were significantly reduced by selective cooling (0.050±0.059 control, 0.005±0.011 hypothermia (ratio stroke:hemisphere volume) (p=0.046). Stroke pathology volumes were reduced by 42% compared with controls (p=0.256).ConclusionsSelective moderate hypothermia was rapidly induced using endovascular techniques in a clinically realistic swine stroke model. A significant reduction in stroke volume on MRI was observed. Endovascular selective hypothermia can provide neuroprotection within time frames relevant to acute ischemic stroke treatment.

Sign in / Sign up

Export Citation Format

Share Document