scholarly journals Root of Angelica gigas Nakai ameliorates ischemic stroke-induced brain injury in mice through the activation of the PI3K/AKT/mTOR and MAPK pathways

2020 ◽  
Author(s):  
Se-Eun Lee ◽  
Chiyeon Lim ◽  
Suin Cho
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Ischemia Reperfusion ◽  
Recombinant Tissue Plasminogen Activator ◽  
Mapk Signaling ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Cresyl Violet ◽  
Neuroprotective Effects ◽  
Cytoplasmic Staining ◽  
Increased Risk

Abstract Background: Ischemic stroke results in disability and increased risk of morbidity, resulting in a massive burden on patients and caregivers. Recombinant tissue plasminogen activator (r-tPA) has a limited window of opportunity for efficacy and causes side effects including hemorrhage; therefore, safer and more effective therapeutic strategies are required. In this study, the neuroprotective effects of a methanolic extract of AGR (AGmex) in ischemia/reperfusion-induced brain injury in mice were investigated. Methods: Ischemic brain injury was induced in the mice by transient occlusion of the middle cerebral artery (tMCAO) for 120 min, and the effect of AGmex on the amount of infarction was measured. Cresyl violet and hematoxylin and eosin stains were used to identify changes in the neurons, nuclei, and cytoplasm. Western blotting, immunohistochemistry, and terminal deoxynucleotidyl transferase dUTP nick end labeling staining were used to elucidate the neuroprotective mechanism of AGmex. Results: AGmex effectively reduced the infarction volume when the mice were pre-treated at 1,000 mg/kg bw/day for two consecutive days (AGmex 1000 group). Neurons, nuclei, and cytoplasmic staining were the lowest in the MCAO group, but recovered in the AGmex 1000 group. In addition, proteins related to cell growth, differentiation, and death were up-regulated in the AGmex 1000 group. Conclusion: The major recovery mechanisms appeared to be attenuation of the mitochondrial function of Bcl-2/Bax, and activation of the PI3K/AKT/mTOR and MAPK signaling pathways in ischemic neurons.

scholarly journals Targeting Platelet GPVI Plus rt-PA Administration but Not α2β1-Mediated Collagen Binding Protects against Ischemic Brain Damage in Mice

2019 ◽  
Vol 20 (8) ◽  
pp. 2019 ◽  
Author(s):  
Michael K. Schuhmann ◽  
Peter Kraft ◽  
Michael Bieber ◽  
Alexander M. Kollikowski ◽  
Harald Schulze ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Recombinant Tissue Plasminogen Activator ◽  
Artery Occlusion ◽  
Stroke Outcome ◽  
Platelet Surface ◽  
Glycoprotein Vi ◽  
Stroke Study ◽  
Increased Risk

Platelet collagen interactions at sites of vascular injuries predominantly involve glycoprotein VI (GPVI) and the integrin α2β1. Both proteins are primarily expressed on platelets and megakaryocytes whereas GPVI expression is also shown on endothelial and integrin α2β1 expression on epithelial cells. We recently showed that depletion of GPVI improves stroke outcome without increasing the risk of cerebral hemorrhage. Genetic variants associated with higher platelet surface integrin α2 (ITGA2) receptor levels have frequently been found to correlate with an increased risk of ischemic stroke in patients. However until now, no preclinical stroke study has addressed whether platelet integrin α2β1 contributes to the pathophysiology of ischemia/reperfusion (I/R) injury. Focal cerebral ischemia was induced in C57BL/6 and Itga2−/− mice by a 60 min transient middle cerebral artery occlusion (tMCAO). Additionally, wild-type animals were pretreated with anti-GPVI antibody (JAQ1) or Fab fragments of a function blocking antibody against integrin α2β1 (LEN/B). In anti-GPVI treated animals, intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment was applied immediately prior to reperfusion. Stroke outcome, including infarct size and neurological scoring was determined on day 1 after tMCAO. We demonstrate that targeting the integrin α2β1 (pharmacologic; genetic) did neither reduce stroke size nor improve functional outcome on day 1 after tMCAO. In contrast, depletion of platelet GPVI prior to stroke was safe and effective, even when combined with rt-PA treatment. Our results underscore that GPVI, but not ITGA2, is a promising and safe target in the setting of ischemic stroke.

Neuroprotective effects of pinocembrin on ischemia/reperfusion-induced brain injury by inhibiting autophagy

2018 ◽  
Vol 106 ◽  
pp. 1003-1010 ◽  
Author(s):  
Jinhao Tao ◽  
Chen Shen ◽  
Yanchun Sun ◽  
Weiming Chen ◽  
Gangfeng Yan
Keyword(s):  
Brain Injury ◽  
Ischemia Reperfusion ◽  
Neuroprotective Effects

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.

Neuroprotection via AT2 receptor agonists in ischemic stroke

2018 ◽  
Vol 132 (10) ◽  
pp. 1055-1067 ◽  
Author(s):  
Douglas M. Bennion ◽  
U. Muscha Steckelings ◽  
Colin Sumners
Keyword(s):  
Ischemic Stroke ◽  
Neuronal Damage ◽  
Recombinant Tissue Plasminogen Activator ◽  
Neurological Deficits ◽  
At2 Receptor ◽  
Neuroprotective Effects ◽  
Receptor Agonists ◽  
Stroke Epidemiology ◽  
The Brain

Stroke is a devastating disease that afflicts millions of people each year worldwide. Ischemic stroke, which accounts for ~88% of cases, occurs when blood supply to the brain is decreased, often because of thromboembolism or atherosclerotic occlusion. This deprives the brain of oxygen and nutrients, causing immediate, irreversible necrosis within the core of the ischemic area, but more delayed and potentially reversible neuronal damage in the surrounding brain tissue, the penumbra. The only currently approved therapies for ischemic stroke, the thrombolytic agent recombinant tissue plasminogen activator (rtPA) and the endovascular clot retrieval/destruction processes, are aimed at restoring blood flow to the infarcted area, but are only available for a minority of patients and are not able in most cases to completely restore neurological deficits. Consequently, there remains a need for agents that will protect neurones against death following ischemic stroke. Here, we evaluate angiotensin II (Ang II) type 2 (AT2) receptor agonists as a possible therapeutic target for this disease. We first provide an overview of stroke epidemiology, pathophysiology, and currently approved therapies. We next review the large amount of preclinical evidence, accumulated over the past decade and a half, which indicates that AT2 receptor agonists exert significant neuroprotective effects in various animal models, and discuss the potential mechanisms involved. Finally, after discussing the challenges of delivering blood–brain barrier (BBB) impermeable AT2 receptor agonists to the infarcted areas of the brain, we summarize the evidence for and against the development of these agents as a promising therapeutic strategy for ischemic stroke.

scholarly journals AP-1 (Activated Protein-1) Transcription Factor JunD Regulates Ischemia/Reperfusion Brain Damage via IL-1β (Interleukin-1β)

Stroke ◽  
2019 ◽  
Vol 50 (2) ◽  
pp. 469-477 ◽  
Author(s):  
Candela Diaz-Cañestro ◽  
Martin F. Reiner ◽  
Nicole R. Bonetti ◽  
Luca Liberale ◽  
Mario Merlini ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Acute Ischemic Stroke ◽  
Peripheral Blood ◽  
Ischemia Reperfusion ◽  
Interleukin 1Β ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes

Background and Purpose— Inflammation is a major pathogenic component of ischemia/reperfusion brain injury, and as such, interventions aimed at inhibiting inflammatory mediators promise to be effective strategies in stroke therapy. JunD—a member of the AP-1 (activated protein-1) family of transcription factors—was recently shown to regulate inflammation by targeting IL (interleukin)-1β synthesis and macrophage activation. The purpose of the present study was to assess the role of JunD in ischemia/reperfusion-induced brain injury. Methods— WT (wild type) mice randomly treated with either JunD or scramble (control) siRNA were subjected to 45 minutes of transient middle cerebral artery occlusion followed by 24 hours of reperfusion. Stroke size, neurological deficit, plasma/brain cytokines, and oxidative stress determined by 4-hydroxynonenal immunofluorescence staining were evaluated 24 hours after reperfusion. Additionally, the role of IL-1β was investigated by treating JunD siRNA mice with an anti–IL-1β monoclonal antibody on reperfusion. Finally, JunD expression was assessed in peripheral blood monocytes isolated from patients with acute ischemic stroke. Results— In vivo JunD knockdown resulted in increased stroke size, reduced neurological function, and increased systemic inflammation, as confirmed by higher neutrophil count and lymphopenia. Brain tissue IL-1β levels were augmented in JunD siRNA mice as compared with scramble siRNA, whereas no difference was detected in IL-6, TNF-α (tumor necrosis factor-α), and 4-hydroxynonenal levels. The deleterious effects of silencing of JunD were rescued by treating mice with an anti–IL-1β antibody. In addition, JunD expression was decreased in peripheral blood monocytes of patients with acute ischemic stroke at 6 and 24 hours after onset of stroke symptoms compared with sex- and age-matched healthy controls. Conclusions— JunD blunts ischemia/reperfusion-induced brain injury via suppression of IL-1β.

scholarly journals YES-10, A Combination of Extracts from Clematis mandshurica RUPR. and Erigeron annuus (L.) PERS., Prevents Ischemic Brain Injury in A Gerbil Model of Transient Forebrain Ischemia

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 154 ◽  
Author(s):  
Tae-Kyeong Lee ◽  
Joon Ha Park ◽  
Bora Kim ◽  
Young Eun Park ◽  
Jae-Chul Lee ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cresyl Violet ◽  
Neuroprotective Effects ◽  
Traditional Medicines ◽  
Neuronal Nuclei ◽  
Cresyl Violet Staining ◽  
Fluoro Jade B ◽  
Erigeron Annuus

Clematis mandshurica RUPR. (CMR) and Erigeron annuus (L.) PERS. (EALP) have pharmacological effects including anti-inflammatory activity and been used in traditional medicines in Asia. However, neuroprotective effects of CMR and/or EALP extracts against brain ischemic insults have never been addressed. Thus, the aim of this study was to examine neuroprotective effects of YES-10, a combination of extracts from CMR and EALP (combination ratio, 1:1), in the hippocampus following ischemia/reperfusion in gerbils. Protection of neurons was investigated by cresyl violet staining, fluoro-jade B histofluorescence staining and immunohistochemistry for neuronal nuclei. In addition, attenuation of gliosis was studied by immunohistochemistry for astrocytic and microglial markers. Treatments with 50 or 100 mg/kg YES-10 failed to protect neurons in the hippocampus after ischemia/reperfusion injury. However, administration of 200 mg/kg YES-10 protected neurons from ischemia/reperfusion injury and attenuated reactive gliosis. These findings strongly suggest that a combination of extracts from CMR and EALP can be used as a prevention approach/drug against brain ischemic damage.

scholarly journals ROS-Dependent Neuroprotective Effects of NaHS in Ischemia Brain Injury Involves the PARP/AIF Pathway

2015 ◽  
Vol 36 (4) ◽  
pp. 1539-1551 ◽  
Author(s):  
Qian Yu ◽  
Zhihong Lu ◽  
Lei Tao ◽  
Lu Yang ◽  
Yu Guo ◽  
...  
Keyword(s):  
Brain Injury ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Dependent Manner ◽  
Neuroprotective Effects ◽  
Ht22 Cells ◽  
In Vivo Models ◽  
The Brain

Background/Aims: Stroke is among the top causes of death worldwide. Neuroprotective agents are thus considered as potentially powerful treatment of stroke. Methods: Using both HT22 cells and male Sprague-Dawley rats as in vitro and in vivo models, we investigated the effect of NaHS, an exogenous donor of H2S, on the focal cerebral ischemia-reperfusion (I/R) induced brain injury. Results: Administration of NaHS significantly decreased the brain infarcted area as compared to the I/R group in a dose-dependent manner. Mechanistic studies demonstrated that NaHS-treated rats displayed significant reduction of malondialdehyde content, and strikingly increased activity of superoxide dismutases and glutathione peroxidase in the brain tissues compared with I/R group. The enhanced antioxidant capacity as well as restored mitochondrial function are NaHS-treatment correlated with decreased cellular reactive oxygen species level and compromised apoptosis in vitro or in vivo in the presence of NaHS compared with control. Further analysis revealed that the inhibition of PARP-1 cleavage and AIF translocation are involved in the neuroprotective effects of NaHS. Conclusion: Collectively, our results suggest that NaHS has potent protective effects against the brain injury induced by I/R. NaHS is possibly effective through inhibition of oxidative stress and apoptosis.

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