scholarly journals Comparative Cerebroprotective Potential of d- and l-Carnosine Following Ischemic Stroke in Mice

2020 ◽  
Vol 21 (9) ◽  
pp. 3053
Author(s):  
Saurabh Jain ◽  
Eun-Sun Kim ◽  
Donghyun Kim ◽  
David Burrows ◽  
Milena De Felice ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Time Window ◽  
Focal Cerebral Ischemia ◽  
Similar Efficacy ◽  
Human Studies ◽  
Experimental Stroke ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures

l-carnosine is an attractive therapeutic agent for acute ischemic stroke based on its robust preclinical cerebroprotective properties and wide therapeutic time window. However, large doses are needed for efficacy because carnosine is rapidly degraded in serum by carnosinases. The need for large doses could be particularly problematic when translating to human studies, as humans have much higher levels of serum carnosinases. We hypothesized that d-carnosine, which is not a substrate for carnosinases, may have a better pharmacological profile and may be more efficacious at lower doses than l-carnosine. To test our hypothesis, we explored the comparative pharmacokinetics and neuroprotective properties of d- and L-carnosine in acute ischaemic stroke in mice. We initially investigated the pharmacokinetics of d- and L-carnosine in serum and brain after intravenous (IV) injection in mice. We then investigated the comparative efficacy of d- and l-carnosine in a mouse model of transient focal cerebral ischemia followed by in vitro testing against excitotoxicity and free radical generation using primary neuronal cultures. The pharmacokinetics of d- and l-carnosine were similar in serum and brain after IV injection in mice. Both d- and l-carnosine exhibited similar efficacy against mouse focal cerebral ischemia. In vitro studies in neurons showed protection against excitotoxicity and the accumulation of free radicals. d- and l-carnosine exhibit similar pharmacokinetics and have similar efficacy against experimental stroke in mice. Since humans have far higher levels of carnosinases, d-carnosine may have more favorable pharmacokinetics in future human studies.

scholarly journals α2-Adrenoceptors do not Mediate Neuroprotection in Acute Ischemic Stroke in Mice

2011 ◽  
Vol 31 (10) ◽  
pp. e1-e7 ◽  
Author(s):  
Marc Brede ◽  
Stefan Braeuninger ◽  
Friederike Langhauser ◽  
Lutz Hein ◽  
Norbert Roewer ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Artery Occlusion ◽  
Experimental Stroke ◽  
Blood Pressure Lowering Effect ◽  
Α2 Adrenoceptors ◽  
Arterial Blood ◽  
Neuroprotective Function

We assessed the neuroprotective potential of α2-adrenoceptors in ischemic stroke using mice with targeted deletions of individual α2-adrenoceptor subtypes (α 2A−/−, α 2B−/−, α 2C−/−, α 2A/C−/−). The effects of the α2-adrenoceptor agonist clonidine were studied in parallel. Focal cerebral ischemia was induced with or without clonidine pretreatment by transient middle cerebral artery occlusion. Neurologic outcome and infarct volumes were evaluated on day 1. Cerebral blood flow (CBF) and mean arterial pressure were determined. α2- Adrenoceptor null mice did not display larger infarct volumes compared with wild-type (WT) mice under basal conditions ( P>0.05). In line with this finding, pretreatment with clonidine did not protect from ischemic brain damage in WT mice or α 2A−/−, α 2B−/−, and α 2C−/− mice. Clonidine induced smaller infarct volumes only in α 2A/C−/− mice ( P < 0.05), but this did not translate into improved neurologic function ( P > 0.05). Importantly, while clonidine caused a significant decrease in arterial blood pressure in all groups, it had no blood pressure lowering effect in α 2A/C−/− mice, and this correlated with higher CBF and smaller infarct volumes in this group. In summary, we could not demonstrate a neuroprotective function of α2-adrenoceptors in focal cerebral ischemia. Careful controlling of physiological parameters relevant for stroke outcome is recommended in experimental stroke studies.

scholarly journals Evaluation of the PBR/TSPO Radioligand [18F]DPA-714 in a Rat Model of Focal Cerebral Ischemia

2009 ◽  
Vol 30 (1) ◽  
pp. 230-241 ◽  
Author(s):  
Abraham Martín ◽  
Raphaël Boisgard ◽  
Benoit Thézé ◽  
Nadja Van Camp ◽  
Bertrand Kuhnast ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Pet Imaging ◽  
Time Course ◽  
Focal Cerebral Ischemia ◽  
Quantitative Information ◽  
Translocator Protein ◽  
Experimental Stroke ◽  
Tspo Expression

Focal cerebral ischemia leads to an inflammatory reaction involving an overexpression of the peripheral benzodiazepine receptor (PBR)/18-kDa translocator protein (TSPO) in the cerebral monocytic lineage (microglia and monocyte) and in astrocytes. Imaging of PBR/TSPO by positron emission tomography (PET) using radiolabeled ligands can document inflammatory processes induced by cerebral ischemia. We performed in vivo PET imaging with [18F]DPA-714 to determine the time course of PBR/TSPO expression over several days after induction of cerebral ischemia in rats. In vivo PET imaging showed significant increase in DPA ( N,N-diethyl-2-(2-(4-(2-fluoroethoxy)phenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl)acetamide) uptake on the injured side compared with that in the contralateral area on days 7, 11, 15, and 21 after ischemia; the maximal binding value was reached 11 days after ischemia. In vitro autoradiography confirmed these in vivo results. In vivo and in vitro [18F]DPA-714 binding was displaced from the lesion by PK11195 and DPA-714. Immunohistochemistry showed increased PBR/TSPO expression, peaking at day 11 in cells expressing microglia/macrophage antigens in the ischemic area. At later times, a centripetal migration of astrocytes toward the lesion was observed, promoting the formation of an astrocytic scar. These results show that [18F]DPA-714 provides accurate quantitative information of the time course of PBR/TSPO expression in experimental stroke.

scholarly journals Knockout of Silent Information Regulator 2 (SIRT2) Preserves Neurological Function after Experimental Stroke in Mice

2015 ◽  
Vol 35 (12) ◽  
pp. 2080-2088 ◽  
Author(s):  
Lea Krey ◽  
Fred Lühder ◽  
Kathrin Kusch ◽  
Bozena Czech-Zechmeister ◽  
Birte Könnecke ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Brain Regions ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Experimental Stroke ◽  
Wild Type ◽  
Significant Difference ◽  
Stroke Models

Sirtuin-2 (Sirt2) is a member of the NAD+-dependent protein deacetylase family. Various members of the sirtuin class have been found to be involved in processes related to longevity, regulation of inflammation, and neuroprotection. Induction of Sirt2 mRNA was found in the whole hemisphere after experimental stroke in a recent screening approach. Moreover, Sirt2 protein is highly expressed in myelin-rich brain regions after stroke. To examine the effects of Sirt2 on ischemic stroke, we induced transient focal cerebral ischemia in adult male Sirt2-knockout and wild-type mice. Two stroke models with different occlusion times were applied: a severe ischemia (45 minutes of middle cerebral artery occlusion (MCAO)) and a mild one (15 minutes of MCAO), which was used to focus on subcortical infarcts. Neurological deficit was determined at 48 hours after 45 minutes of MCAO, and up to 7 days after induction of 15 minutes of cerebral ischemia. In contrast to recent data on Sirt1, Sirt2−/− mice showed less neurological deficits in both models of experimental stroke, with the strongest manifestation after 48 hours of reperfusion. However, we did not observe a significant difference of stroke volumes or inflammatory cell count between Sirt2-deficient and wild-type mice. Thus we postulate that Sirt2 mediates myelin-dependent neuronal dysfunction during the early phase after ischemic stroke.

scholarly journals Dihydrolipoate Reduces Neuronal Injury after Cerebral Ischemia

1992 ◽  
Vol 12 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Jochen H. M. Prehn ◽  
Chourouk Karkoutly ◽  
Jörg Nuglisch ◽  
Barbara Peruche ◽  
Josef Krieglstein
Keyword(s):  
Cerebral Ischemia ◽  
Neuronal Damage ◽  
Brain Infarction ◽  
Neuronal Injury ◽  
Artery Occlusion ◽  
Neuroprotective Activity ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures

It has been shown in vitro that dihydrolipoate (dl-6,8-dithioloctanoic acid) has antioxidant activity against microsomal lipid peroxidation. We tested dihydrolipoate for its neuroprotective activity using models of hypoxic and excitotoxic neuronal damage in vitro and rodent models of cerebral ischemia in vivo. In vitro, neuronal damage was induced in primary neuronal cultures derived form 7-day-old chick embryo telencephalon by adding either 1 m M cyanide or 1 m M glutamate to the cultures. Cyanide-exposed and dihydrolipoate-treated (10−9–10−7 M) cultures showed an increased protein and ATP content compared with controls. The glutamate-exposed cultures treated with dihydrolipoate (10−7–10−5 M) showed a decreased number of damaged neurons. In vivo, dihydrolipoate treatment (50 and 100 mg/kg) reduced brain infarction after permanent middle cerebral artery occlusion in mice and rats. Dihydrolipoate treatment (50 and 100 mg/kg) could not ameliorate neuronal damage in the rat hippocampus or cortex caused by 10 min of forebrain ischemia. A comparable neuroprotection was obtained by using dimethylthiourea, both in vitro (10−7 and 10−6 M) and at a dose of 750 mg/kg in the focal ischemia models. Lipoate, the oxidized form of dihydrolipoate, failed to reduce neuronal injury in any model tested. We conclude that dihydrolipoate, similarly to dimethylthiourea, is able to protect neurons against ischemic damage by diminishing the accumulation of reactive oxygen species within the cerebral tissue.

scholarly journals Different Strokes for Different Folks: The Rich Diversity of Animal Models of Focal Cerebral Ischemia

2010 ◽  
Vol 30 (8) ◽  
pp. 1412-1431 ◽  
Author(s):  
David W Howells ◽  
Michelle J Porritt ◽  
Sarah SJ Rewell ◽  
Victoria O'Collins ◽  
Emily S Sena ◽  
...  
Keyword(s):  
Animal Model ◽  
Ischemic Stroke ◽  
Animal Models ◽  
Focal Cerebral Ischemia ◽  
Experimental Stroke ◽  
Stroke Outcome ◽  
Rich Diversity ◽  
Single Animal ◽  
The Rich ◽  
Use Of Models

No single animal model is able to encompass all of the variables known to affect human ischemic stroke. This review highlights the major strengths and weaknesses of the most commonly used animal models of acute ischemic stroke in the context of matching model and experimental aim. Particular emphasis is placed on the relationships between outcome and underlying vascular variability, physiologic control, and use of models of comorbidity. The aim is to provide, for novice and expert alike, an overview of the key controllable determinants of experimental stroke outcome to help ensure the most effective application of animal models to translational research.

scholarly journals Neuroprotection by Brazilian Green Propolis againstIn vitroandIn vivoIschemic Neuronal Damage

2005 ◽  
Vol 2 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Masamitsu Shimazawa ◽  
Satomi Chikamatsu ◽  
Nobutaka Morimoto ◽  
Satoshi Mishima ◽  
Hiroichi Nagai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Neuronal Damage ◽  
Focal Cerebral Ischemia ◽  
Brain Infarction ◽  
Folk Medicine ◽  
Neuroprotective Function ◽  
Brazilian Green Propolis

We examined whether Brazilian green propolis, a widely used folk medicine, has a neuroprotective functionin vitroand/orin vivo.In vitro, propolis significantly inhibited neurotoxicity induced in neuronally differentiated PC12 cell cultures by either 24 h hydrogen peroxide (H2O2) exposure or 48 h serum deprivation. Regarding the possible underlying mechanism, propolis protected against oxidative stress (lipid peroxidation) in mouse forebrain homogenates and scavenged free radicals [induced by diphenyl-p-picrylhydrazyl (DPPH). In micein vivo, propolis [30 or 100 mg/kg; intraperitoneally administered four times (at 2 days, 1 day and 60 min before, and at 4 h after induction of focal cerebral ischemia by permanent middle cerebral artery occlusion)] reduced brain infarction at 24 h after the occlusion. Thus, a propolis-induced inhibition of oxidative stress may be partly responsible for its neuroprotective function againstin vitrocell death andin vivofocal cerebral ischemia.

scholarly journals Senolytic Therapy for Cerebral Ischemia-Reperfusion Injury

2021 ◽  
Vol 22 (21) ◽  
pp. 11967
Author(s):  
Songhyun Lim ◽  
Tae Jung Kim ◽  
Young-Ju Kim ◽  
Cheesue Kim ◽  
Sang-Bae Ko ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Inflammatory Cytokines ◽  
Cellular Senescence ◽  
Therapeutic Potential ◽  
Ischemia Reperfusion ◽  
Severe Disabilities ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ir Injury

Ischemic stroke is one of the leading causes of death, and even timely treatment can result in severe disabilities. Reperfusion of the ischemic stroke region and restoration of the blood supply often lead to a series of cellular and biochemical consequences, including generation of reactive oxygen species (ROS), expression of inflammatory cytokines, inflammation, and cerebral cell damage, which is collectively called cerebral ischemia-reperfusion (IR) injury. Since ROS and inflammatory cytokines are involved in cerebral IR injury, injury could involve cellular senescence. Thus, we investigated whether senolytic therapy that eliminates senescent cells could be an effective treatment for cerebral IR injury. To determine whether IR induces neural cell senescence in vitro, astrocytes were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). OGD/R induced astrocyte senescence and senescent cells in OGD/R-injured astrocytes were effectively eliminated in vitro by ABT263, a senolytic agent. IR in rats with intraluminal middle cerebral artery occlusion induced cellular senescence in the ischemic region. The senescent cells in IR-injured rats were effectively eliminated by intravenous injections of ABT263. Importantly, ABT263 treatment significantly reduced the infarct volume and improved neurological function in behavioral tests. This study demonstrated, for the first time, that senolytic therapy has therapeutic potential for cerebral IR injury.

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 Nuclear Translocation of Apoptosis-Inducing Factor after Focal Cerebral Ischemia

2004 ◽  
Vol 24 (4) ◽  
pp. 458-466 ◽  
Author(s):  
Nikolaus Plesnila ◽  
Changlian Zhu ◽  
Carsten Culmsee ◽  
Moritz Gröger ◽  
Michael A. Moskowitz ◽  
...  
Keyword(s):  
Cell Death ◽  
Cerebral Ischemia ◽  
Cytochrome C ◽  
Nuclear Translocation ◽  
Focal Cerebral Ischemia ◽  
Mitochondrial Protein ◽  
Neuronal Cell ◽  
Experimental Stroke ◽  
Cytochrome C Release ◽  
Apoptosis Inducing Factor

Signaling cascades associated with apoptosis contribute to cell death after focal cerebral ischemia. Cytochrome c release from mitochondria and the subsequent activation of caspases 9 and 3 are critical steps. Recently, a novel mitochondrial protein, apoptosis-inducing factor (AIF), has been implicated in caspase-independent programmed cell death following its translocation to the nucleus. We, therefore, addressed the question whether AIF also plays a role in cell death after focal cerebral ischemia. We detected AIF relocation from mitochondria to nucleus in primary cultured rat neurons 4 and 8 hours after 4 hours of oxygen/glucose deprivation. In ischemic mouse brain, AIF was detected within the nucleus 1 hour after reperfusion after 45 minutes occlusion of the middle cerebral artery. AIF translocation preceded cell death, occurred before or at the time when cytochrome c was released from mitochondria, and was evident within cells showing apoptosis-related DNA fragmentation. From these findings, we infer that AIF may be involved in neuronal cell death after focal cerebral ischemia and that caspase-independent signaling pathways downstream of mitochondria may play a role in apoptotic-like cell death after experimental stroke.

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