Evidence for the Use of Isoflurane as a Replacement for Chloral Hydrate Anesthesia in Experimental Stroke: An Ethical Issue

Since an ethical issue has been raised regarding the use of the well-known anesthetic agent chloral hydrate, owing to its mutagenic and carcinogenic effects in animals, attention of neuroscientists has turned to finding out an alternative agent able to meet not only potency, safety, and analgesic efficacy, but also reduced neuroprotective effect for stroke research. The aim of this study was to compare the potential of chloral hydrate and isoflurane for both modulating the action of the experimental neuroprotectant MK801 and exerting analgesia. After middle cerebral artery occlusion in rats, no difference was observed in 24 h survival rate, success of ischemia, or infarct volume reduction between both anesthetics. However, isoflurane exerted a more pronounced analgesic effect than chloral hydrate as evidenced by formalin test 3 hours after anesthesia onset, thus encouraging the use of isoflurane in experimental stroke models.

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The hypoxia sensitive metal transcription factor MTF-1 activates NCX1 brain promoter and participates in remote postconditioning neuroprotection in stroke

Cell Death and Disease ◽

10.1038/s41419-021-03705-9 ◽

2021 ◽

Vol 12 (5) ◽

Author(s):

Valeria Valsecchi ◽

Giusy Laudati ◽

Ornella Cuomo ◽

Rossana Sirabella ◽

Lucio Annunziato ◽

...

Keyword(s):

Transcription Factor ◽

Brain Ischemia ◽

Femoral Artery ◽

Infarct Volume ◽

Neuroprotective Effect ◽

Artery Occlusion ◽

Sodium Calcium Exchanger ◽

Protein Levels ◽

Relevant Role ◽

Remote Postconditioning

AbstractRemote limb ischemic postconditioning (RLIP) is an experimental strategy in which short femoral artery ischemia reduces brain damage induced by a previous harmful ischemic insult. Ionic homeostasis maintenance in the CNS seems to play a relevant role in mediating RLIP neuroprotection and among the effectors, the sodium-calcium exchanger 1 (NCX1) may give an important contribution, being expressed in all CNS cells involved in brain ischemic pathophysiology. The aim of this work was to investigate whether the metal responsive transcription factor 1 (MTF-1), an important hypoxia sensitive transcription factor, may (i) interact and regulate NCX1, and (ii) play a role in the neuroprotective effect mediated by RLIP through NCX1 activation. Here we demonstrated that in brain ischemia induced by transient middle cerebral occlusion (tMCAO), MTF-1 is triggered by a subsequent temporary femoral artery occlusion (FAO) and represents a mediator of endogenous neuroprotection. More importantly, we showed that MTF-1 translocates to the nucleus where it binds the metal responsive element (MRE) located at −23/−17 bp of Ncx1 brain promoter thus activating its transcription and inducing an upregulation of NCX1 that has been demonstrated to be neuroprotective. Furthermore, RLIP restored MTF-1 and NCX1 protein levels in the ischemic rat brain cortex and the silencing of MTF-1 prevented the increase of NCX1 observed in RLIP protected rats, thus demonstrating a direct regulation of NCX1 by MTF-1 in the ischemic cortex of rat exposed to tMCAO followed by FAO. Moreover, silencing of MTF-1 significantly reduced the neuroprotective effect elicited by RLIP as demonstrated by the enlargement of brain infarct volume observed in rats subjected to RLIP and treated with MTF-1 silencing. Overall, MTF-dependent activation of NCX1 and their upregulation elicited by RLIP, besides unraveling a new molecular pathway of neuroprotection during brain ischemia, might represent an additional mechanism to intervene in stroke pathophysiology.

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Abstract P746: Sex Differences in Cognitive and Psychological Outcomes of Stroke: Impact of Diabetes

Stroke ◽

10.1161/str.52.suppl_1.p746 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Victoria L Wolf ◽

Aunay Miller ◽

Raghavendar Chandran ◽

Weiguo Li ◽

Adviye Ergul

Keyword(s):

Artery Occlusion ◽

Psychological Outcomes ◽

Experimental Stroke ◽

Dark Light ◽

Stroke Outcomes ◽

Post Stroke ◽

Stroke Research ◽

Y Maze ◽

Male Animal ◽

The Impact

Diabetes increases risk and severity of post-stroke cognitive impairment (PSCI), a major cause of disability worldwide. While it is known that females suffer more from PSCI, psychological outcomes and underlying reasons are poorly understood. From a preclinical perspective, potential explanations include 1) use of otherwise healthy animals in experimental stroke research without integration of common comorbid diseases like diabetes into the study design, and 2) optimization of most behavioral tests for sensorimotor and cognitive functions using only male animal models. Our hypothesis is that post-stroke outcomes are sex and comorbid disease-dependent. To test this, we validated the Novel Object Recognition (NOR), Y-maze, and Passive Avoidance (PAT) behavioral paradigms in Ctrl and Diabetic (DM) male (M) and female (F) rats pre- and post-stroke (S) via 60 min. middle cerebral artery occlusion (MCAO). We tested the PAT paradigm with a multi-trial method where the animals were habituated to the dark/light chambers without foot shock and then trained in 3 trials where they received foot shock upon entering the dark. We then tested retention following MCAO for their memory of foot shock 2 weeks prior. Multitrial results suggested that there was no difference between groups in learning to associate the dark chamber with the shock, so we revised the multitrial method into a single-trial method for ongoing retention tests to compare the impact of stroke on shock memory recall. PAT revealed (Table 1) disease- and sex-dependent responses to aversive stimulus. NOR revealed that M-DM-S and F-DM-S rats have decreased exploration time, suggesting that they are unmotivated or depressed. Y-maze indicated that males displayed spatial memory recovery, while females remained impaired. In summary, we have observed numerous sex- and disease-dependent post-stroke outcomes with standard behavioral paradigms, causing us to carefully consider how we evaluate preclinical outcomes.

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Abstract WP118: The Flavanol (-)-Epicatechin Improves Functional Recovery In Mice Subjected To Experimental Stroke

Stroke ◽

10.1161/str.44.suppl_1.awp118 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Christopher C Leonardo ◽

Sean Robbins ◽

Abdullah A Ahmad ◽

Sylvain Dore

Keyword(s):

Functional Recovery ◽

Transcriptional Activation ◽

Infarct Volume ◽

Epidemiological Studies ◽

Artery Occlusion ◽

Experimental Stroke ◽

Adhesive Tape ◽

Dietary Consumption ◽

Therapeutic Doses ◽

Cerebral Artery Occlusion

Background: Epidemiological studies indicate that flavanol consumption reduces the propensity to develop cerebrovascular disease. Available data suggest actions on multiple pro-inflammatory pathways, yet it remains unclear which pathways mediate functional recovery after stroke. Our goal is to begin identifying the mechanisms by which the flavanol (-)-epicatechin (EC) improves anatomical and functional outcomes. Based upon data from initial dose-response experiments, ongoing studies are investigating hypothesized protective pathways involving matrix metalloproteinase-mediated blood brain barrier protection and Nrf2 transcriptional activation. Methods: Male, 8-10wk old C57BL/6 mice were pretreated with EC 90m prior to permanent distal middle cerebral artery occlusion. Vehicle or EC was administered by oral gavage to mimic dietary consumption. Mice were evaluated 1, 4 and 7d post-stroke for performance on various sensorimotor tasks prior to histological assessments. Results: Initial experiments demonstrated that mice treated with 15mg/kg EC showed reduced latency to remove adhesive tape at 1d compared to vehicle controls (n=12, p<0.01). Similarly, immunoreactivity for the microglia/macrophage marker Iba1 was increased in the ipsilateral hemispheres of mice 7d after treatment with vehicle (p<0.01), whereas pretreatment with 15mg/kg blocked this effect (n=4). Mice treated with 15mg/kg also showed a trend toward reduced infarct volume relative to vehicle controls (n=5-9 per group). In subsequent reduced dosing studies, vehicle-treated mice again showed deficiencies in removing adhesive tape at 1d (n=8, p<0.01). Remarkably, mice treated with 15, 10 or 5mg/kg EC showed no deficits. Similarly, vehicle control mice showed grip strength impairments up to 7d (n=8, p<0.05) that were absent in all groups of EC-treated mice. Conclusions: Preventative administration of EC promotes functional recovery in mice subjected to experimental stroke. Investigations are underway to determine the pathways mediated by EC following administration at these therapeutic doses. Together, these data will provide insights into the potential for (-)-epicatechin as a clinical therapeutic.

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Abstract WP272: A Powerful Combination Therapy for Stroke: Post-Ischemia Ethanol Administration and Normobaric Oxygenation on Ischemic Rats

Stroke ◽

10.1161/str.44.suppl_1.awp272 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Christopher Sy ◽

Xiaokun Geng ◽

Paul Fu ◽

Changya Peng ◽

Vance Fredrickson ◽

...

Keyword(s):

Combination Therapy ◽

Protein Expression ◽

Infarct Volume ◽

Neuroprotective Effect ◽

Artery Occlusion ◽

Neurological Deficits ◽

Ethanol Administration ◽

Acute Administration ◽

Sprague Dawley ◽

Acute Cerebral Ischemia

Objectives: Normobaric oxygenation (NBO) has been reported to be neuroprotective against acute cerebral ischemia. Recently, a clinical trial was terminated because beneficial outcomes were not definitive. Our recent study ( Stroke. 2012 43(1):205-10 ) demonstrated a strong neuroprotective effect induced by acute administration of ethanol (EtOH) at 1.5g/kg. In this study, we assessed the therapeutic influence of EtOH in combination with NBO. Methods: Sprague-Dawley rats were subjected to right middle cerebral artery occlusion for 2h. Ischemic animals received either an intraperitoneal injection of EtOH (1.0g/kg), a course of NBO (100% for 2h), or a combination of both immediately prior to reperfusion onset. Brain injury was determined by infarct volume and behavioral outcomes at 48h post-reperfusion. Metabolic dysfunction was investigated by assessing ADP/ATP ratios, reactive oxygen species (ROS) levels, NADPH oxidase (NOX) activity, and protein expression of NOX subunits (p47 phox , gp91 phox , and p67 phox ), as well as the protein expression and enzyme activity of pyruvate dehydrogenase (PDH), at both 3h and 24h after reperfusion. Results: Combination therapy led to a significant decrease in infarct volumes (Saline: 48±4%, EtOH: 38±3%, NBO: 37±4%, Combination: 19±3% ) and in neurological deficits (Belayev Scale 0-12, Saline: 8.4±0.7; EtOH: 6.5±0.7; NBO: 6.4±0.6; Combination: 4.4±0.3 ). At 3h and 24h post-reperfusion the decrease in ADP/ATP ratio was significantly enhanced, reflecting a preservation of cellular energy. A greater decrease in NOX activity and protein expression was observed, in association with decreased ROS levels, suggesting that improved glycolysis may contribute to neuroprotection. PDH activity and protein expression was dramatically increased, making the facilitation of aerobic metabolism a probable mechanism for preserving cellular ATP. Conclusions: Our findings demonstrate that a synergistic relationship exists between EtOH and NBO. Both are promising neuroprotective agents when used together, even at low doses. Moreover, both are inexpensive, widely available, easy to administer, and have little side effects. Thus, combination therapy could be an effective and efficient approach to future stroke treatments.

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Comorbidity and age in the modelling of stroke: are we still failing to consider the characteristics of stroke patients?

BMJ Open Science ◽

10.1136/bmjos-2019-100013 ◽

2020 ◽

Vol 4 (1) ◽

pp. e100013 ◽

Cited By ~ 3

Author(s):

Sarah K McCann ◽

Catherine B Lawrence

Keyword(s):

Infarct Volume ◽

Treatment Options ◽

Response To Treatment ◽

Experimental Stroke ◽

Preclinical Studies ◽

Stroke Patients ◽

Mortality And Morbidity ◽

Degree Of Protection ◽

Stroke Research ◽

Drug Interventions

Stroke is a significant cause of mortality and morbidity for which there are limited treatment options. Virtually all drug interventions that have been successful preclinically in experimental stroke have failed to translate to an effective treatment in the clinical setting. In this review, we examine one of the factors likely contributing to this lack of translation, the failure of preclinical studies to consider fully the advanced age and comorbidities (eg, hypertension or diabetes) present in most patients with stroke. Age and comorbidities affect the likelihood of suffering a stroke, disease progression and the response to treatment. Analysing data from preclinical systematic reviews of interventions for ischaemic stroke we show that only 11.4% of studies included an aged or comorbid model, with hypertension being the most frequent. The degree of protection (% reduction in infarct volume) varied depending on the comorbidity and the type of intervention. We consider reasons for the lack of attention to comorbid and aged animals in stroke research and discuss the value of testing a potential therapy in models representing a range of comorbidities that affect patients with stroke. These models can help establish any limits to a treatment’s efficacy and inform the design of clinical trials in appropriate patient populations.

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Oxytocin Mediates Social Neuroprotection After Cerebral Ischemia

Stroke ◽

10.1161/strokeaha.111.628008 ◽

2011 ◽

Vol 42 (12) ◽

pp. 3606-3611 ◽

Cited By ~ 60

Author(s):

Kate Karelina ◽

Kathleen A. Stuller ◽

Brant Jarrett ◽

Ning Zhang ◽

Jackie Wells ◽

...

Keyword(s):

Cerebral Ischemia ◽

Receptor Antagonist ◽

Social Housing ◽

Neuroprotective Effect ◽

Artery Occlusion ◽

Experimental Stroke ◽

Stroke Outcome ◽

Socially Isolated ◽

Cerebral Artery Occlusion ◽

And Oxidative Stress

Background and Purpose— The reduced incidence, morbidity, and mortality of stroke among humans with strong social support have been well-documented; however, the mechanisms underlying these socially mediated phenomena remain unknown, but may involve oxytocin (OT), a hormone that modulates some aspects of social behavior in humans and other animals. Methods— In the present study, adult male mice were socially isolated (housed individually) or socially paired (housed with an ovariectomized female); social pairing increased hypothalamic OT gene expression. To determine whether a causal relationship exists between increased OT and improved stroke outcome, mice were treated with exogenous OT or OT receptor antagonist beginning 1 week before induction of experimental stroke via middle cerebral artery occlusion. Results— Relative to social isolation, social housing attenuated infarct size, neuroinflammation, and oxidative stress following experimental stroke; the neuroprotective effect of social housing was eliminated by receptor antagonist treatment. In contrast, administration of OT to socially isolated mice reproduced the neuroprotection conferred by social housing. We further report evidence for a direct suppressive action of OT on cultured microglia, which is a key instigator in the development of neuroinflammation after cerebral ischemia. Conclusions— These findings support the hypothesis that OT mediates the neuroprotective effect of social interaction on stroke outcome.

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Power spectrum slope and motor function recovery after focal cerebral ischemia in the rat

10.1101/242388 ◽

2018 ◽

Cited By ~ 1

Author(s):

Susan Leemburg ◽

Bo Gao ◽

Ertugrul Cam ◽

Johannes Sarnthein ◽

Claudio L. Bassetti

Keyword(s):

Power Spectrum ◽

Motor Function ◽

Focal Cerebral Ischemia ◽

Recovery Period ◽

Artery Occlusion ◽

Experimental Stroke ◽

Stroke Models ◽

Eeg Changes ◽

Cerebral Artery Occlusion ◽

Spectrum Slope

AbstractEEG changes across vigilance states have been observed after ischemic stroke in patients and experimental stroke models, but their relation to functional recovery remains unclear. Here, we evaluate motor function, as measured by single pellet reaching (SPR), as well as local EEG changes in NREM, REM and wakefulness during a 30-day recovery period after middle cerebral artery occlusion (MCAO) or sham surgery in rats. Small cortical infarcts resulted in poor SPR performance and induced widespread changes in EEG spectra in the ipsilesional hemisphere in all vigilance states, without causing major changes in sleep-wake architecture. Ipsilesional 1–4 Hz power was increased after stroke, whereas power in higher frequencies was reduced, resulting in a steeper slope of the power spectrum. Multielectrode array analysis of ipsilesional M1 showed that these spectral changes were present on the microelectrode level throughout M1 and were not related to increased synchronization between electrodes. Spectrum slope was significantly correlated with post-stroke motor function.

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MiR-29a Knockout Aggravates Neurological Damage by Pre-polarizing M1 Microglia in Experimental Rat Models of Acute Stroke

Frontiers in Genetics ◽

10.3389/fgene.2021.642079 ◽

2021 ◽

Vol 12 ◽

Author(s):

Fangfang Zhao ◽

Haiping Zhao ◽

Junfen Fan ◽

Rongliang Wang ◽

Ziping Han ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Stroke ◽

Molecular Mechanisms ◽

Infarct Volume ◽

Glutamate Release ◽

Artery Occlusion ◽

Experimental Stroke ◽

Neurological Damage ◽

Stroke Patients ◽

Rat Models

ObjectiveBy exploring the effects of miR-29a-5p knockout on neurological damage after acute ischemic stroke, we aim to deepen understanding of the molecular mechanisms of post-ischemic injury and thus provide new ideas for the treatment of ischemic brain injury.MethodsmiR-29a-5p knockout rats and wild-type SD rats were subjected to transient middle cerebral artery occlusion (MCAO). miR-29a levels in plasma, cortex, and basal ganglia of ischemic rats, and in plasma and neutrophils of ischemic stroke patients, as well as hypoxic glial cells were detected by real-time PCR. The infarct volume was detected by TTC staining and the activation of astrocytes and microglia was detected by western blotting.ResultsThe expression of miR-29a-5p was decreased in parallel in blood and brain tissue of rat MCAO models. Besides, miR-29a-5p levels were reduced in the peripheral blood of acute stroke patients. Knockout of miR-29a enhanced infarct volume of the MCAO rat model, and miR-29a knockout showed M1 polarization of microglia in the MCAO rat brain. miR-29a knockout in rats after MCAO promoted astrocyte proliferation and increased glutamate release.ConclusionKnockout of miR-29a in rats promoted M1 microglial polarization and increased glutamate release, thereby aggravating neurological damage in experimental stroke rat models.

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Chronic T cell proliferation in brains after stroke could interfere with the efficacy of immunotherapies

Journal of Experimental Medicine ◽

10.1084/jem.20202411 ◽

2021 ◽

Vol 218 (8) ◽

Author(s):

Steffanie Heindl ◽

Alessio Ricci ◽

Olga Carofiglio ◽

Qihui Zhou ◽

Thomas Arzberger ◽

...

Keyword(s):

Cell Proliferation ◽

T Cell ◽

Critical Role ◽

Experimental Stroke ◽

T Cell Proliferation ◽

Ischemic Brain ◽

Stroke Research ◽

Cell Accumulation ◽

Circulating Lymphocytes ◽

Stroke Models

Neuroinflammation is an emerging focus of translational stroke research. Preclinical studies have demonstrated a critical role for brain-invading lymphocytes in post-stroke pathophysiology. Reducing cerebral lymphocyte invasion by anti-CD49d antibodies consistently improves outcome in the acute phase after experimental stroke models. However, clinical trials testing this approach failed to show efficacy in stroke patients for the chronic outcome 3 mo after stroke. Here, we identify a potential mechanistic reason for this phenomenon by detecting chronic T cell accumulation—evading the systemic therapy—in the post-ischemic brain. We observed a persistent accumulation of T cells in mice and human autopsy samples for more than 1 mo after stroke. Cerebral T cell accumulation in the post-ischemic brain was driven by increased local T cell proliferation rather than by T cell invasion. This observation urges re-evaluation of current immunotherapeutic approaches, which target circulating lymphocytes for promoting recovery after stroke.

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Abstract WP152: Novel Therapy With Pdgf-b Nanoparticles for Cerebral Infarction

Stroke ◽

10.1161/str.51.suppl_1.wp152 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Soh Takagishi ◽

Koichi Arimura ◽

Katsuma Iwaki ◽

Ataru Nishimura ◽

Masaharu Murata ◽

...

Keyword(s):

Cerebral Infarction ◽

Infarct Volume ◽

Neuroprotective Effect ◽

Reperfusion Therapy ◽

Artery Occlusion ◽

Neurological Function ◽

Novel Therapy ◽

Infarct Area ◽

Neurotrophin 3 ◽

Cerebral Artery Occlusion

Background and Purpose: Treatment for cerebral infarction beyond the indication of reperfusion therapy has not yet been established, and novel approaches are needed. It has been reported that platelet-derived growth factor (PDGF)-B played a neuroprotective role by enhancing cell survival and tissue repair for a long period after cerebral infarction in experimental animal models. However, PDGF-B is difficult to administer at effective concentrations in infarct area. In general, nanoparticles are very small and stable, making them prone to accumulation without being metabolized in infarct area. Therefore, we converted PDGF-B into nanoparticles and examined its therapeutic effect for cerebral infarction. Methods: PDGF-B nanoparticles (PDGF-B NP) and wild-type nanoparticles (wNP) were injected one day after transient middle cerebral artery occlusion (tMCAO) using the CB-17 mouse model. We analyzed temporal histological changes and neurological function recovery. Fucntional recovery was assess using Cylinder test at 3 and 7 days after the tMCAO. As for the mechanism of neuroprotective effect, phosphorylation of Akt, neurotrophin-3 (NT-3), and expression of angiogenesis were also examined in the infarct area and compared them with wNP control at 7 days after tMCAO. Result: We found that PDGF-B NP was distributed specifically in the infarct area. As compared with wNP group, PDGF-B NP group significantly suppressed cerebral infarct volume and improved neurological function at 3 and 7 days after cerebral infarction compared with wNP group. Akt was strongly phosphorylated in the infarction area with PDGF-B NP administration compared with wNP. Moreover, PDGF-B NP significantly induced angiogenesis, NT-3 expression, and reduced cell apoptosis after cerebral infarction compared with wNP. Conclusion: PDGF-B NP activated PDGF-B-Akt signaling in infarct area and played various important roles leading to neuroprotection after cerebral infarction. Our results suggested that treatment with PDGF-B NP may be useful for cerebral infarction beyond reperfusion therapy.

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