scholarly journals Post-stroke treatment with argon preserved neurons and attenuated microglia/macrophage activation long-termly in a rat model of transient middle cerebral artery occlusion (tMCAO)

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Jingjin Liu ◽  
Michael Veldeman ◽  
Anke Höllig ◽  
Kay Nolte ◽  
Lisa Liebenstund ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Macrophage Activation ◽  
Neuroprotective Effect ◽  
Macrophage Polarization ◽  
Artery Occlusion ◽  
Brain Inflammation ◽  
Long Term Effects ◽  
Neuroprotective Effects ◽  
Stroke Treatment

AbstractIn a previous study from our group, argon has shown to significantly attenuate brain injury, reduce brain inflammation and enhance M2 microglia/macrophage polarization until 7 days after ischemic stroke. However, the long-term effects of argon have not been reported thus far. In the present study, we analyzed the underlying neuroprotective effects and potential mechanisms of argon, up to 30 days after ischemic stroke. Argon administration with a 3 h delay after stroke onset and 1 h after reperfusion demonstrated long-term neuroprotective effect by preserving the neurons at the ischemic boundary zone 30 days after stroke. Furthermore, the excessive microglia/macrophage activation in rat brain was reduced by argon treatment 30 days after ischemic insult. However, long-lasting neurological improvement was not detectable. More sensorimotor functional measures, age- and disease-related models, as well as further histological and molecular biological analyses will be needed to extend the understanding of argon’s neuroprotective effects and mechanism of action after ischemic stroke.

scholarly journals Notoginsenoside R1 Improves Cerebral Ischemia/Reperfusion Injury by Promoting Neurogenesis via the BDNF/Akt/CREB Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Ting Zhu ◽  
Lei Wang ◽  
Weijie Xie ◽  
Xiangbao Meng ◽  
Yicheng Feng ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Functional Recovery ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Neurological Function ◽  
Long Term Effects ◽  
Bdnf Expression ◽  
Neuroprotective Effects

Notoginsenoside R1 (R1), a major component isolated from P. notoginseng, is a phytoestrogen that exerts many neuroprotective effects in a rat model of ischemic stroke. However, its long-term effects on neurogenesis and neurological restoration after ischemic stroke have not been investigated. The aim of this study was to evaluate the effects of R1 on neurogenesis and long-term functional recovery after ischemic stroke. We used male Sprague-Dawley rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). R1 was administered by intraperitoneal (i.p.) injection immediately postischemia. We showed that R1 significantly decreased infarct volume and neuronal loss, restored neurological function, and stimulated neurogenesis and oligodendrogenesis in rats subjected to MCAO/R. More importantly, R1 promoted neuronal proliferation in PC12 cells in vitro. The proneurogenic effects of R1 were associated with the activation of Akt/cAMP responsive element-binding protein, as shown by the R1-induced increase in brain-derived neurotrophic factor (BDNF) expression, and with the activation of neurological function, which was partially eliminated by selective inhibitors of BDNF and PI3K. We demonstrated that R1 is a promising compound that exerts neuroprotective and proneurogenic effects, possibly via the activation of BDNF/Akt/CREB signaling. These findings offer insight into exploring new mechanisms in long-term functional recovery after R1 treatment of ischemic stroke.

scholarly journals Mesenchymal Stem Cell Derived Extracellular Vesicles for Repairing the Neurovascular Unit after Ischemic Stroke

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 767
Author(s):  
Courtney Davis ◽  
Sean I. Savitz ◽  
Nikunj Satani
Keyword(s):  
Ischemic Stroke ◽  
Extracellular Vesicles ◽  
Neurovascular Unit ◽  
Culture Conditions ◽  
Therapeutic Effects ◽  
Stroke Treatment ◽  
Inflammatory Molecules ◽  
The Brain

Ischemic stroke is a debilitating disease and one of the leading causes of long-term disability. During the early phase after ischemic stroke, the blood-brain barrier (BBB) exhibits increased permeability and disruption, leading to an influx of immune cells and inflammatory molecules that exacerbate the damage to the brain tissue. Mesenchymal stem cells have been investigated as a promising therapy to improve the recovery after ischemic stroke. The therapeutic effects imparted by MSCs are mostly paracrine. Recently, the role of extracellular vesicles released by these MSCs have been studied as possible carriers of information to the brain. This review focuses on the potential of MSC derived EVs to repair the components of the neurovascular unit (NVU) controlling the BBB, in order to promote overall recovery from stroke. Here, we review the techniques for increasing the effectiveness of MSC-based therapeutics, such as improved homing capabilities, bioengineering protein expression, modified culture conditions, and customizing the contents of EVs. Combining multiple techniques targeting NVU repair may provide the basis for improved future stroke treatment paradigms.

scholarly journals Long-Term Caloric Restriction Attenuates β-Amyloid Neuropathology and Is Accompanied by Autophagy in APPswe/PS1delta9 Mice

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 985
Author(s):  
Luisa Müller ◽  
Nicole Power Guerra ◽  
Jan Stenzel ◽  
Claire Rühlmann ◽  
Tobias Lindner ◽  
...  
Keyword(s):  
Caloric Restriction ◽  
Neuroprotective Effect ◽  
Resonance Spectroscopy ◽  
Neuroprotective Effects ◽  
Beneficial Effects ◽  
Positron Emission ◽  
Pet Ct ◽  
Amyloid Aβ ◽  
Β Amyloid

Caloric restriction (CR) slows the aging process, extends lifespan, and exerts neuroprotective effects. It is widely accepted that CR attenuates β-amyloid (Aβ) neuropathology in models of Alzheimer’s disease (AD) by so-far unknown mechanisms. One promising process induced by CR is autophagy, which is known to degrade aggregated proteins such as amyloids. In addition, autophagy positively regulates glucose uptake and may improve cerebral hypometabolism—a hallmark of AD—and, consequently, neural activity. To evaluate this hypothesis, APPswe/PS1delta9 (tg) mice and their littermates (wild-type, wt) underwent CR for either 16 or 68 weeks. Whereas short-term CR for 16 weeks revealed no noteworthy changes of AD phenotype in tg mice, long-term CR for 68 weeks showed beneficial effects. Thus, cerebral glucose metabolism and neuronal integrity were markedly increased upon 68 weeks CR in tg mice, indicated by an elevated hippocampal fluorodeoxyglucose [18F] ([18F]FDG) uptake and increased N-acetylaspartate-to-creatine ratio using positron emission tomography/computer tomography (PET/CT) imaging and magnet resonance spectroscopy (MRS). Improved neuronal activity and integrity resulted in a better cognitive performance within the Morris Water Maze. Moreover, CR for 68 weeks caused a significant increase of LC3BII and p62 protein expression, showing enhanced autophagy. Additionally, a significant decrease of Aβ plaques in tg mice in the hippocampus was observed, accompanied by reduced microgliosis as indicated by significantly decreased numbers of iba1-positive cells. In summary, long-term CR revealed an overall neuroprotective effect in tg mice. Further, this study shows, for the first time, that CR-induced autophagy in tg mice accompanies the observed attenuation of Aβ pathology.

scholarly journals Impacts of treatments on recurrence and 28-year survival of ischemic stroke patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ting-Ann Wang ◽  
Tzy-Haw Wu ◽  
Shin-Liang Pan ◽  
Hsiu-Hsi Chen ◽  
Sherry Yueh-Hsia Chiu
Keyword(s):  
Ischemic Stroke ◽  
Cerebrovascular Disease ◽  
Cox Regression ◽  
Controlled Trial ◽  
Stroke Recurrence ◽  
Long Term Effects ◽  
Stroke Patients ◽  
Double Blind ◽  
Term Survival

AbstractAspirin and nicametate are well-established therapies for preventing recurrence and mortality from stroke in patients diagnosed as ischemic stroke. However, their respective effects on the recurrence, making allowance for the duration of recurrence and death without the occurrence of recurrence, and long-term survival have not been well elucidated. We aimed to evaluate long-term effect of two kinds of treatment on cerebrovascular death among ischemic stroke patients with or without the recurrence of stroke. Data used in this study were derived from the cohort based on a multicenter randomized double-blind controlled trial during 1992 to 1995 with the enrollment of a total of 466 patients with first-time non-cardioembolic ischemic stroke who were randomly allocated to receive aspirin (n = 222) or nicametate (n = 244). The trial cohort was followed up over time to ascertain the date of recurrence within trial period and death until Sep of 2019. The time-dependent Cox regression model was used to estimate the long-term effects of two treatments on death from cerebrovascular disease with and without recurrence. A total of 49 patients experienced stroke recurrence and 89 cerebrovascular deaths was confirmed. Patients treated with nicametate were more likely, but non statistically significantly, to have recurrence (aHR: 1.73, 95% CI 0.96–3.13) as compared with those treated by aspirin. Nicametate reduced the risk of cerebrovascular death about 37% (aHR: 0.63, 95% CI 0.41–0.97) compared with aspirin. The aspirin group had a lower recurrence rate than the nicametate group even with recurrence after 1–2 years of follow-up of first stroke but the latter had significantly reduced death from cerebrovascular disease for nicametate group, which requires more research to verify.

scholarly journals Cerebral endothelial cell-derived small extracellular vesicles enhance neurovascular function and neurological recovery in rat acute ischemic stroke models of mechanical thrombectomy and embolic stroke treatment with tPA

2021 ◽  
pp. 0271678X2199298
Author(s):  
Chao Li ◽  
Chunyang Wang ◽  
Yi Zhang ◽  
Owais K Alsrouji ◽  
Alex B Chebl ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Extracellular Vesicles ◽  
Mechanical Thrombectomy ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Therapeutic Effects ◽  
Vessel Occlusion ◽  
Healthy Human ◽  
Stroke Treatment

Treatment of patients with cerebral large vessel occlusion with thrombectomy and tissue plasminogen activator (tPA) leads to incomplete reperfusion. Using rat models of embolic and transient middle cerebral artery occlusion (eMCAO and tMCAO), we investigated the effect on stroke outcomes of small extracellular vesicles (sEVs) derived from rat cerebral endothelial cells (CEC-sEVs) in combination with tPA (CEC-sEVs/tPA) as a treatment of eMCAO and tMCAO in rat. The effect of sEVs derived from clots acquired from patients who had undergone mechanical thrombectomy on healthy human CEC permeability was also evaluated. CEC-sEVs/tPA administered 4 h after eMCAO reduced infarct volume by ∼36%, increased recanalization of the occluded MCA, enhanced cerebral blood flow (CBF), and reduced blood-brain barrier (BBB) leakage. Treatment with CEC-sEVs given upon reperfusion after 2 h tMCAO significantly reduced infarct volume by ∼43%, and neurological outcomes were improved in both CEC-sEVs treated models. CEC-sEVs/tPA reduced a network of microRNAs (miRs) and proteins that mediate thrombosis, coagulation, and inflammation. Patient-clot derived sEVs increased CEC permeability, which was reduced by CEC-sEVs. CEC-sEV mediated suppression of a network of pro-thrombotic, -coagulant, and -inflammatory miRs and proteins likely contribute to therapeutic effects. Thus, CEC-sEVs have a therapeutic effect on acute ischemic stroke by reducing neurovascular damage.

scholarly journals Replicating infant astrocyte behavior in the adult after brain injury improves outcomes

2020 ◽  
Author(s):  
Leon Teo ◽  
Anthony G. Boghdadi ◽  
Jihane Homman-Ludiye ◽  
Iñaki Carril-Mundiñano ◽  
William C. Kwan ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Brain Injuries ◽  
Adult Patients ◽  
Long Term Outcomes ◽  
Neuroprotective Effects ◽  
Age Dependent ◽  
Underlying Mechanisms ◽  
Glial Scarring

AbstractInfants and adults respond differently to brain injuries. Specifically, improved neuronal sparing along with reduced astrogliosis and glial scarring often observed earlier in life, likely contributes to improved long-term outcomes. Understanding the underlying mechanisms could enable the recapitulation of neuroprotective effects, observed in infants, to benefit adult patients after brain injuries. We reveal that in primates, Eph/ ephrin signaling contributes to age-dependent reactive astrocyte behavior. Ephrin-A5 expression on astrocytes was more protracted in adults, whereas ephrin-A1 was associated only with infant astrocytes. Furthermore, ephrin-A5 exacerbated major hallmarks of astrocyte reactivity via EphA2 and EphA4 receptors, which was subsequently alleviated by ephrin-A1. Rather than suppressing reactivity, ephrin-A1 signaling shifted astrocytes towards GAP43+ neuroprotection, accounting for improved neuronal sparing in infants. Reintroducing ephrin-A1 after middle-aged ischemic stroke significantly attenuated glial scarring, improved neuronal sparing and preserved circuitry. Therefore, beneficial infant mechanisms can be recapitulated in adults to improve outcomes after CNS injuries.

N-Myc Downstream-Regulated Gene 2 (Ndrg2): A Critical Mediator of Estrogen-Induced Neuroprotection Against Cerebral Ischemic Injury

2021 ◽  
Author(s):  
Lixia Zhang ◽  
Yulong Ma ◽  
Min Liu ◽  
Miao Sun ◽  
Jin Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Neuroprotective Effect ◽  
Ischemic Injury ◽  
Artery Occlusion ◽  
Male Mice ◽  
Neuroprotective Effects ◽  
Female Mice ◽  
Ndrg2 Expression ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

Abstract Growing evidence indicates that estrogen plays a pivotal role in neuroprotection against cerebral ischemia, but the molecular mechanism of this protection is still elusive. N-myc downstream‐regulated gene 2 (Ndrg2), an estrogen-targeted gene, has been shown to exert neuroprotective effects against cerebral ischemia in male mice. However, the role of Ndrg2 in the neuroprotective effect of estrogen remains unknown. In this study, we first detected NDRG2 expression levels in the cortex and striatum in both female and male mice with western blot analyses. We then detected cerebral ischemic injury by constructing middle cerebral artery occlusion and reperfusion (MCAO-R) models in Ndrg2 knockout or conditional knockdown female mice. We further implemented estrogen, ERα or ERβ agonist replacement in the ovariectomized (OVX) Ndrg2 knockouts or conditional knockdowns female mice, then tested for NDRG2 expression, glial fibrillary acidic protein (GFAP) expression, and extent of cerebral ischemic injury. We found that NDRG2 expression was significantly higher in female than in male mice in both the cortex and striatum. Ndrg2 knockouts and conditional knockdowns showed significantly aggravated cerebral ischemic injury in female mice. Estrogen and ERβ replacement treatment (DPN) led to NDRG2 upregulation in both the cortex and striatum of OVX mice. Estrogen and DPN also led to GFAP upregulation in OVX mice. However, the effect of estrogen and DPN in activating astrocytes was lost in Ndrg2 knockouts OVX mice and primary cultured astrocytes, but partially retained in conditional knockdowns OVX mice. Most importantly, we found that the neuroprotective effects of E2 and DPN against cerebral ischemic injury were lost in Ndrg2 knockouts OVX mice but partially retained in conditional knockdowns OVX mice. These findings demonstrate that estrogen alleviated cerebral ischemic injury via ERβ upregulation of Ndrg2, which could activate astrocytes, indicating that Ndrg2 is a critical mediator of E2-induced neuroprotection against cerebral ischemic injury.

scholarly journals A System for Continuous Pre- to Post-reperfusion Intra-carotid Cold Infusion for Selective Brain Hypothermia in Rodent StrokeModels

2020 ◽  
Author(s):  
Yi Wang ◽  
Jae H. Choi ◽  
Mohammed A. Almekhlafi ◽  
Ulf Ziemann ◽  
Sven Poli
Keyword(s):  
Ischemic Stroke ◽  
Artery Occlusion ◽  
Brain Cooling ◽  
Sprague Dawley ◽  
Total Blood ◽  
Pilot Studies ◽  
Stroke Treatment ◽  
Stroke Models ◽  
Cold Infusion ◽  
Cerebral Artery Occlusion

Abstract Intra-carotid cold infusion (ICCI) appears as a promising method for hypothermia-mediated brain protection from ischemic stroke. Recent clinical pilot studies indicate easy implementation of ICCI into endovascular acute ischemic stroke treatment. Current rodent ICCI-in-stroke models limit ICCI to the post-reperfusion phase. To establish a method for continuous ICCI over the duration of intra-ischemia to post-reperfusion in rodent stroke models, a novel system was developed. Eighteen male Sprague-Dawley rats were included. Intraluminal filament method was used for transient middle cerebral artery occlusion (MCAO). Normal saline (~ 0 °C) was delivered (≤ 2.0 mL/min) into the internal carotid artery via a customized infusion system without interruption during MCAO (intra-ischemia) to after filament withdrawal (post-reperfusion). Bilateral cortical and striatal temperatures were monitored. Hypothermia goals were a temperature reduction in the ischemic hemisphere by 2 °C prior to reperfusion and thereafter maintenance of regional brain hypothermia at ~ 32 °C limiting the administered ICCI volume to ½ of each rat’s total blood volume. During ischemia, maximum brain cooling rate was achieved with ICCI at 0.5 mL/min. It took 2 min to reduce ischemic striatal temperature by 2.3 ± 0.3 °C. After reperfusion, brain cooling was continued at 2 mL/min ICCI first (over 42 s) and maintained at 32.1 ± 0.3 °C at 0.7 mL/min ICCI over a duration of 15 ± 0.8 min. ICCI (total 12.6 ± 0.6 mL) was uninterrupted over the duration of the studied phases. First system that allows continuous ICCI during the phases of intra-ischemia to post-reperfusion in small animals for selective brain cooling and for investigations of other neuroprotective infusions.

scholarly journals Twenty-Year Time Trends in Long-Term Case-Fatality and Recurrence Rates After Ischemic Stroke Stratified by Etiology

Stroke ◽  
2020 ◽  
Vol 51 (9) ◽  
pp. 2778-2785 ◽  
Author(s):  
Viktoria Rücker ◽  
Peter U. Heuschmann ◽  
Martin O’Flaherty ◽  
Michael Weingärtner ◽  
Manuela Hess ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Time Trends ◽  
Cox Regression ◽  
Case Fatality ◽  
Population Based ◽  
Artery Occlusion ◽  
Recurrence Rates ◽  
Term Survival ◽  
Small Artery Occlusion

Background and Purpose: Data on long-term survival and recurrence after stroke are lacking. We investigated time trends in ischemic stroke case-fatality and recurrence rates over 20-years stratified by etiological subtype according to the Trial of ORG 10172 in Acute Stroke Treatment classification within a population-based stroke register in Germany. Methods: Data was collected within the Erlangen Stroke Project, a prospective, population-based stroke register covering a source population of 105 164 inhabitants (2010). Case fatality and recurrence rates for 3 months, 1 year, and 5 years were estimated with Kaplan-Meier estimates. Sex-specific time trends for case-fatality and recurrence rates were estimated with Cox regression. We adjusted for age, sex, and year of event and stratified for etiological subtypes. A sensitivity analysis with competing risk analysis for time trends in recurrence were performed. Results: Between 1996 and 2015, 3346 patients with first ischemic stroke were included; age-standardized incidence per 100 000 was 75.8 in women and 131.6 in men (2015). Overall, 5-year survival probabilities were 50.4% (95% CI, 47.9–53.1) in women and 59.2% (95% CI, 56.4–62.0) in men; 5-year survival was highest in patients with first stroke due to small-artery occlusion (women, 71.8% [95% CI, 67.1–76.9]; men, 75.9% [95% CI, 71.3–80.9]) and lowest in cardioembolic stroke (women, 35.7% [95% CI, 31.0–41.1]; men, 47.8% [95% CI, 42.2–54.3]). Five-year recurrence rates were 20.1% (95% CI, 17.5–22.6) in women and 20.1% (95% CI, 17.5–22.7) in men; 5-year recurrence rate was lowest in women in stroke due to small artery occlusion 16.0% (95% CI, 11.7–20.1) and in men in large-artery atherosclerosis 16.6% (95% CI, 8.7–23.9); highest risk of recurrence was observed in undefined strokes (women, 22.3% [95% CI, 17.8–26.6]; men, 21.4% [95% CI, 16.7–25.9]). Cox regression revealed improvements in case-fatality rates over time with differences in stroke causes. No time trends in recurrence rates were observed. Conclusions: Long-term survival and recurrence varied substantially by first stroke cause. Survival probabilities improved over the past 2 decades; no major trends in stroke recurrence rates were observed.

Can the Use of Oral Minocycline Improve Ischemic Stroke Outcomes?

2008 ◽  
Vol 21 (2) ◽  
pp. 159-164
Author(s):  
Kathy B. Lee
Keyword(s):  
United States ◽  
Ischemic Stroke ◽  
The United States ◽  
Sudden Onset ◽  
Pharmacological Agents ◽  
Stroke Outcomes ◽  
Stroke Treatment ◽  
The Brain ◽  
Brain Ischemic Stroke

Cerebrovascular accident (CVA), also known as ischemic stroke, is the sudden onset of neurologic deficit attributable to a focal vascular cause.1 It is the third leading cause of death, with the death rate being reported as 50.0 (per 100,000 population) in the United States in 2004.2 It is also a leading cause for serious, long-term disability in the United States. While there are various causes, the large majority of strokes result from either global or focal ischemia of the brain. Ischemic stroke accounts for 87% of all strokes, while intracerebral and subarachnoid hemorrhage makes up the remainder. 2 Currently, the primary pharmacological agents used in stroke treatment are thrombolytics, not without limitations, however, and antiplatelet therapy. 3 Minocycline, a semisynthetic tetracycline antibiotic, has recently gained attention as a neuroprotective agent. A recent study evaluated the use of minocycline in the treatment of acute stroke and demonstrated promising results.4 A review of the mechanisms of action and data presented in past studies will be examined to evaluate the efficacy and clinical impact of minocycline in the treatment of acute ischemic stroke.

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